MissingReferenceException thrown when deleting a Cinemachine Camera with the CinemachinePixelPerfect extension

Steps to reproduce:

1. Create and open a new 2D URP project
2. Install the Cinemachine package in Window -> Package Management -> Package Manager
3. Create a Cinemachine Camera
4. Add the "CinemachinePixelPerfect" extension in the Inspector
5. Delete the Cinemachine Camera
6. Observe the Console

Actual results: A "MissingReferenceException: The object of type 'Unity.Cinemachine.CinemachinePixelPerfect' has been destroyed but you are still trying to access it." error is thrown

Expected results: Nothing is thrown

Reproducible with versions: 3.1.5 (6000.4.0a5), 3.1.6 (6000.6.0a5)

Not reproducible with versions: 3.1.4 (6000.4.0a5)

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• Reproducible with any Cinemachine-based Camera