fix: keep the bridge when a script adds it before the NetworkObject

NetworkObjectBridge.OnValidate queued a DestroyImmediate whenever no NetworkObject was present yet. Test helpers (and user scripts) add the bridge first, so the bridge was destroyed after the prefab was set up, breaking every unified hybrid test. The deferred call now checks again before destroying.

Author: NoelStephensUnity

com.unity.netcode.gameobjects/Runtime/Components/Helpers/NetworkObjectBridge.cs

@@ -31,8 +31,14 @@ private void OnValidate()
             var networkObject = GetComponent<NetworkObject>();
             if (networkObject == null)
             {
-                // Remove the bridge if there is no NetworkObject
-                EditorApplication.delayCall += () => DestroyImmediate(this, true);
+                // Check again once the current operation finishes, since a script can add the bridge before the NetworkObject.
+                EditorApplication.delayCall += () =>
+                {
+                    if (this != null && GetComponent<NetworkObject>() == null)
+                    {
+                        DestroyImmediate(this, true);
+                    }
+                };
             }
             else
             {