Use a Java 8 set for the DB target type powers

The dev build compiles as Java 8, which has no Set.of.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/gameManager/PowersManager.java

@@ -35,6 +35,7 @@ import engine.server.MBServerStatics;
 import org.pmw.tinylog.Logger;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -60,7 +61,7 @@ public enum PowersManager {
     public static HashMap<Integer, ArrayList<RuneSkillAdjustEntry>> _allRuneSkillAdjusts;
     public static HashMap<String, HashMap<ResourceType, Integer>> _effect_costMaps = new HashMap<>();
     // Succor, Phaedra's Fury and Fleet of Foot keep their DB target type until the Phase 4 power task decides them
-    private static final Set<String> DB_TARGET_TYPE_POWERS = Set.of("HLR-025", "HNT-023", "RNG-033");
+    private static final Set<String> DB_TARGET_TYPE_POWERS = new HashSet<>(Arrays.asList("HLR-025", "HNT-023", "RNG-033"));
     private static JobScheduler js;
 
     public static void initPowersManager(boolean fullPowersLoad) {