fix: adapt /fly OP permission check to 1.21.11 PermissionPredicate API

src/main/java/top/gtb520/java/mods/openfly/Commands/fly.java

@@ -3,6 +3,7 @@ package top.gtb520.java.mods.openfly.Commands;
 import com.mojang.brigadier.Command;
 import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback;
 import net.fabricmc.fabric.api.entity.event.v1.ServerLivingEntityEvents;
+import net.minecraft.command.DefaultPermissions;
 import net.minecraft.command.argument.EntityArgumentType;
 import net.minecraft.entity.damage.DamageTypes;
 import net.minecraft.server.command.CommandManager;
@@ -42,7 +43,7 @@ public class fly {
                             })
                             // /fly <player> - 切换指定玩家的飞行状态（需要OP权限）
                             .then(CommandManager.argument("player", EntityArgumentType.player())
-                                    .requires(source -> source.hasPermissionLevel(2))
+                                    .requires(source -> source.getPermissions().hasPermission(DefaultPermissions.GAMEMASTERS))
                                     .executes(context -> {
                                         ServerPlayerEntity targetPlayer = EntityArgumentType.getPlayer(context, "player");
                                         UUID playerId = targetPlayer.getUuid();