Changing Editor Style breaks animation window buttons

Steps to reproduce:

1. Create a new project 
2. Add a GameObject to a scene
3. Open the animation window and create a new clip for the GameObject
4. Note the Preview and Record buttons can be intereacted with
5. Open Preferences and change the Editor Theme.
6. The Preview and Record button can no longer be interacted with.

Actual results: Can still press the preview and record button

Expected results: The Preview and Record button can no longer be interacted with.

Reproducible with versions: 6000.3.0a2

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): Windows 11

Notes:

• Looks like a bug with m_Driver going null in GetAnimationModeDriverNoAlloc.