Added install_without_dependencies.sh file

This is a modification of the current install.sh file, that works like that one, but without trying to install all the dependencies for you, which could cause some problems in outdated systems or not supported distros.
Also, install.sh file is outdated and doesn't work right now. This should be fixed, but for now, I prefer to have a separated and less intrusive script that does the same but without asking for dependencies.
This script can be also used for updating the current installation of Grasscutter if is run in the root folder of the server, removing the resources folder and giving some instructions on how to correctly update the server so you try them before starting to think that the update is just broken.
If you consider this unnecessary, please don't hesitate to cancel the PR.

install_without_dependencies.sh

+#!/usr/bin/env bash
+
+# Grasscutter install script for linux - Simpler version
+# This installer doesn't ask you to install dependencies, you have to install them manually
+# Made by TurtleIdiot and modified by syktyvkar (and then again modified by Blue)
+
+# Stops the installer if any command has a non-zero exit status
+set -e
+
+# Checks for root
+if [ $EUID != 0 ]; then
+    echo "Please run the installer as root (sudo)!"
+    exit
+fi
+
+is_command() {
+    # Checks if given command is available
+    local check_command="$1"
+    command -v "${check_command}" > /dev/null 2>&1
+}
+
+# IP validation
+valid_ip() {
+    local ip=$1
+    local stat=1
+
+    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+        OIFS=$IFS
+        IFS="."
+        ip=($ip)
+        IFS=$OIFS
+        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
+            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
+        stat=$?
+    fi
+    return $stat
+}
+echo "#################################"
+echo ""
+echo "This script will take for granted that you have all dependencies installed (mongodb, openjdk-17-jre/jre17-openjdk, wget, openssl, unzip, git, curl, base-devel), in fact, this script is recommended to update your current server installation, and it should run from the same folder as grasscutter.jar"
+echo "#################################"
+echo ""
+echo "If you are using version > 2.8 of the client, make sure to use the patched metadata if you don't use Cultivation."
+echo "Search for METADATA here: https://discord.gg/grasscutter."
+echo ""
+echo "#################################"
+
+echo ""
+echo "Grasscutter will be installed to script's running directory"
+echo "Do you wish to proceed and install Grasscutter?"
+select yn in "Yes" "No" ; do
+    case $yn in
+        Yes ) break;;
+        No )
+			echo "Aborting..."
+			exit;;
+    esac
+done
+
+if [ -d "./resources" ]
+then
+    echo "It's recommended to remove resources folder"
+    echo "Remove resources folder?"
+    select yn in "Yes" "No" ; do
+        case $yn in
+            Yes ) 
+                rm -rf resources
+                break;;
+            No )
+                echo "Aborting..."
+                exit;;
+        esac
+    done
+echo "You may need to remove data folder and config.json to apply some updates"
+echo "#################################"
+fi
+
+
+
+# Allows choice between stable and dev branch
+echo "Please select the branch you wish to install"
+echo -e "!!NOTE!!: stable is the recommended branch.\nDo *NOT* use development unless you have a reason to and know what you're doing"
+select branch in "stable" "development" ; do
+    case $branch in
+        stable )
+            break;;
+        development )
+            break;;
+    esac
+done
+
+echo -e "Using $branch branch for installing server \n"
+
+# Prompt IP address for config.json and for generating new keystore.p12 file
+echo "Please enter the IP address that will be used to connect to the server"
+echo "This can be a local or a public IP address"
+echo "This IP address will be used to generate SSL certificates, so it is important it is correct!"
+
+while : ; do
+    read -p "Enter server IP: " SERVER_IP
+    if valid_ip $SERVER_IP; then
+        break;
+    else
+        echo "Invalid IP address. Try again."
+    fi
+done
+
+echo "Beginning Grasscutter installation..."
+
+
+# Download resources
+echo "Downloading Grasscutter BinOutputs..."
+git clone --single-branch https://github.com/Koko-boya/Grasscutter_Resources.git Grasscutter-bins
+mv ./Grasscutter-bins/Resources ./resources
+rm -rf Grasscutter-bins # takes ~350M of drive space after moving BinOutputs... :sob:
+
+# Download and build jar
+echo "Downloading Grasscutter source code..."
+git clone --single-branch -b $branch https://github.com/Grasscutters/Grasscutter.git Grasscutter-src #change this to download a fork
+
+echo "Building grasscutter.jar..."
+cd Grasscutter-src
+chmod +x ./gradlew #just in case
+./gradlew --no-daemon jar
+mv $(find -name "grasscutter*.jar" -type f) ../grasscutter.jar
+echo "Building grasscutter.jar done!"
+cd ..
+
+# Generate handbook/config
+echo "Grasscutter will be started to generate its data files"
+echo "Please enter language for GM handbook when prompted"
+echo "Grasscutter will stop once GM handbook is generated"
+java -jar grasscutter.jar -handbook
+
+# Replaces "127.0.0.1" with given IP
+echo "Replacing IP address in server config..."
+sed -i "s/127.0.0.1/$SERVER_IP/g" config.json
+
+# Generates new keystore.p12 with the server's IP address
+# This is done to prevent a "Connection Timed Out" error from appearing
+#	   after clicking to enter the door in the main menu/title screen
+# This issue only exists when connecting to a server *other* than localhost
+#	   since the default keystore.p12 has only been made for localhost
+
+mkdir certs
+cd certs
+echo "Generating CA key and certificate pair..."
+openssl req -x509 -nodes -days 25202 -newkey rsa:2048 -subj "/C=GB/ST=Essex/L=London/O=Grasscutters/OU=Grasscutters/CN=$SERVER_IP" -keyout CAkey.key -out CAcert.crt
+
+echo "Generating SSL key and certificate pair..."
+openssl genpkey -out ssl.key -algorithm rsa
+
+# Creates a conf file in order to generate a csr
+cat > csr.conf <<EOF
+[ req ]
+default_bits = 2048
+prompt = no
+default_md = sha256
+req_extensions = req_ext
+distinguished_name = dn
+
+[ dn ]
+C = GB
+ST = Essex
+L = London
+O = Grasscutters
+OU = Grasscutters
+CN = $SERVER_IP
+
+[ req_ext ]
+subjectAltName = @alt_names
+
+[ alt_names ]
+IP.1 = $SERVER_IP
+EOF
+
+# Creates csr using key and conf
+openssl req -new -key ssl.key -out ssl.csr -config csr.conf
+
+# Creates conf to finalise creation of certificate
+cat > cert.conf <<EOF
+
+authorityKeyIdentifier=keyid,issuer
+basicConstraints=CA:FALSE
+keyUsage = digitalSignature, nonRepudiation, keyEncipherment, keyAgreement, dataEncipherment
+subjectAltName = @alt_names
+
+[alt_names]
+IP.1 = $SERVER_IP
+
+EOF
+
+# Creates SSL cert
+openssl x509 -req -in ssl.csr -CA CAcert.crt -CAkey CAkey.key -CAcreateserial -out ssl.crt -days 25202 -sha256 -extfile cert.conf
+
+echo "Generating keystore.p12 from key and certificate..."
+openssl pkcs12 -export -out keystore.p12 -inkey ssl.key -in ssl.crt -certfile CAcert.crt -passout pass:123456
+
+cd ../
+mv ./certs/keystore.p12 ./keystore.p12
+echo "Done!"
+
+# Running scripts as sudo makes all Grasscutter files to be owned by root
+# which may cause problems editing .jsons...
+if [ $SUDO_USER ]; then
+	echo "Changing Grasscutter files owner to current user..."
+	chown -R $SUDO_USER:$SUDO_USER ./*
+fi
+
+echo "Asking Noelle to clean up..."
+rm -rf ./certs ./Grasscutter-src
+
+echo "All done!"
+echo "-=-=-=-=-=--- !! IMPORTANT !! ---=-=-=-=-=-"
+echo "Please make sure that ports 80, 443, 8888 and 22102 are OPEN (both tcp and udp)"
+echo "In order to run the server, run the following command:"
+echo "    sudo java -jar grasscutter.jar"
+echo "You must run it using sudo as port 443 is a privileged port"
+echo "To play, use the IP you provided earlier ($SERVER_IP) via GrassClipper or Fiddler"
+
+exit