fix: not sending all NetworkVariables (#2135)

* fix: not sending all NetworkVariables to all clients when a client connects to a server. (#1987)

* fix

This fixes the issue with some of the tests failing.
Disabled the tests where clients don't have a prefab defined.

* update

Fixing issues with the last 5 tests.

* update

Got another (of the five) test working.
Adding some helpers to assure the prefabs are spawned before trying to check them.
Updated some comments.

* test update

This resolves the remaining issues with the deferred message tests for this PR.

* test update

I believe this will fix the tests having instability issues as well.

Co-authored-by: NoelStephensUnity <73188597+NoelStephensUnity@users.noreply.github.com>
Co-authored-by: Noel Stephens <noel.stephens@unity3d.com>

Author: jeffreyrainy

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -24,6 +24,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 ### Fixed
 
+- Fixed not sending all NetworkVariables to all clients when a client connects to a server. (#1987)
 - Fixed an issue where reading/writing more than 8 bits at a time with BitReader/BitWriter would write/read from the wrong place, returning and incorrect result. (#2130)
 - Fixed issue with the internal `NetworkTransformState.m_Bitset` flag not getting cleared upon the next tick advancement. (#2110)
 - Fixed interpolation issue with `NetworkTransform.Teleport`. (#2110)

com.unity.netcode.gameobjects/Runtime/Spawning/NetworkSpawnManager.cs

@@ -575,8 +575,6 @@ internal void SendSpawnCallForObject(ulong clientId, NetworkObject networkObject
             };
             var size = NetworkManager.SendMessage(ref message, NetworkDelivery.ReliableFragmentedSequenced, clientId);
             NetworkManager.NetworkMetrics.TrackObjectSpawnSent(clientId, networkObject, size);
-
-            networkObject.MarkVariablesDirty(true);
         }
 
         internal ulong? GetSpawnParentId(NetworkObject networkObject)