Hardcode `EventType.GAME` for `ServerLogEvent`

src/main/java/emu/grasscutter/server/event/internal/ServerLogEvent.java

 package emu.grasscutter.server.event.internal;
 
 import ch.qos.logback.classic.spi.ILoggingEvent;
-import ch.qos.logback.core.AppenderBase;
 import emu.grasscutter.server.event.types.ServerEvent;
 
-public class ServerLogEvent extends ServerEvent {
-    ILoggingEvent loggingEvent;
-    String consoleMessage;
+public final class ServerLogEvent extends ServerEvent {
+    private final ILoggingEvent loggingEvent;
+    private final String consoleMessage;
+
+    public ServerLogEvent(ILoggingEvent loggingEvent, String consoleMessage) {
+        super(Type.GAME);
 
-    public ServerLogEvent(Type type, ILoggingEvent loggingEvent, String consoleMessage) {
-        super(type);
         this.loggingEvent = loggingEvent;
         this.consoleMessage = consoleMessage;
     }
 
-    public ILoggingEvent getLoggingEvent() { return loggingEvent; }
+    public ILoggingEvent getLoggingEvent() {
+        return this.loggingEvent;
+    }
 
     public String getConsoleMessage() {
-        return consoleMessage;
+        return this.consoleMessage;
     }
 }

src/main/java/emu/grasscutter/utils/ServerLogEventAppender.java

@@ -17,12 +17,12 @@ public class ServerLogEventAppender<E> extends AppenderBase<E> {
     @Override
     protected void append(E event) {
         byte[] byteArray = this.encoder.encode(event);
-        ServerLogEvent sle = new ServerLogEvent(ServerEvent.Type.GAME, (ILoggingEvent) event, new String(byteArray, StandardCharsets.UTF_8));
+        ServerLogEvent sle = new ServerLogEvent((ILoggingEvent) event, new String(byteArray, StandardCharsets.UTF_8));
         sle.call();
     }
 
     public Encoder<E> getEncoder() {
-        return encoder;
+        return this.encoder;
     }
 
     public void setEncoder(Encoder<E> encoder) {