ci: [NGOv2.X] Fixing WebGL timeout and reenabling macOS job

[michalChrobot]

This PR focuses on investigating often timeouts of WebGL job happening on Ubuntu platform (note that there are no timeouts on Windows) and also on re-enabling macOS job that was disabled due to error "Light baking could not be started because no valid OpenCL device could be found" and is tracked in MTT-11726

When it comes to the error on macOS, the build was failing due to a light baking error in different scenes with message "no valid OpenCL device could be found." This common issue on Apple Silicon VMs, where OpenCL support is often missing for the GPU lightmapper, can be resolved by disabling "Baked Global Illumination" for the scene. Since those scenes in testproject do not really need baked lighting and I didn't spot any difference with this option disabled I went forward with disabling it for testproject scenes and this resolves macOS issue.

For the Ubuntu timeout problem I restored image version to v4 instead of pointing to specific version since the issue that caused us to do so was resolved. I also increased flavor to xlarge (from large) because it seems that with more resources the process is not hanging anymore (will run test 5 times to confirm)

Backport

https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/pull/3511