URP 3D Sample throws Cross scene reference related warning when entert

Steps to reproduce:

1. Create a new URP 3D Sample Template project
2. Enter Play mode
3. Observe the Console window

Actual results: Two Cross scene reference related warnings are thrown

Expected results: No warnings or errors are thrown in Template projects when entering Play mode

Reproducible with versions: 6000.6.0a6, 6000.7.0a2(17.3.0)

Not reproducible with versions: 6000.0.78f1, 6000.3.18f1, 6000.5.3f1(17.2.1), 6000.6.0a5(17.3.0)

Tested on (OS): macOS 26.5.1, Ubuntu 24

Notes:

• Full warning message - Cross scene references are not supported: 'Cinematic Timeline' in scene TerminalScene has an invalid reference to 'MainCamera' in scene DontDestroyOnLoad. This reference will not be saved in the scene.