Remove deprecated function

Author: florianreuth

src/main/java/com/viaversion/fabric/common/provider/AbstractFabricPlatform.java

@@ -175,11 +175,6 @@ public String getPlatformVersion() {
                 .get().getMetadata().getVersion().getFriendlyString();
     }
 
-    @Override
-    public boolean isPluginEnabled() {
-        return true;
-    }
-
     @Override
     public JsonObject getDump() {
         JsonObject platformSpecific = new JsonObject();