Client Game Test Singleplayer Network Synchronizer Error

[kevinthegreat1]

Client game test crashes in CI on xvfb due to

[17:14:58] [Render thread/ERROR] (fabric-client-gametest-api-v1) Detected interfacing with packets at a lower level. Please disable network synchronization by setting the fabric.client.gametest.disableNetworkSynchronizer system property
[17:14:58] [Render thread/ERROR] (Minecraft) Unreported exception thrown!
java.lang.AssertionError: Network synchronizer in invalid state, see earlier log messages
	at knot/net.fabricmc.fabric.impl.client.gametest.NetworkSynchronizer.checkInvalid(NetworkSynchronizer.java:190) ~[fabric-client-gametest-api-v1-3.2.0+a069796e04.jar:?]

Analysis by earthcomputer: https://discord.com/channels/507304429255393322/566276937035546624/1335800385041862777
Full logs here: https://github.com/SkyblockerMod/Skyblocker/actions/runs/13100838528/job/36548902394