fix(hs): roll back team reservation if TryEnterAsync throws

src/GameLogic/MiniGames/HeykelSavasiContext.cs

@@ -160,19 +160,26 @@ public class HeykelSavasiContext : MiniGameContext
             return false;
         }
 
+        var success = false;
+        try
+        {
             var enterResult = await this.TryEnterAsync(player).ConfigureAwait(false);
-        if (enterResult != EnterResult.Success)
+            success = enterResult == EnterResult.Success;
+        }
+        finally
+        {
+            if (!success)
             {
                 lock (this._teamLock)
                 {
-                // Roll back the reservation; the player never actually entered the mini game.
+                    // Roll back the reservation; the player never actually entered the mini game
+                    // (or TryEnterAsync threw, e.g. due to a disconnect/disposal race).
                     this.RemoveTeam(player);
                 }
-
+            }
-            return false;
         }
 
-        return true;
+        return success;
     }
 
     /// <summary>