Undoing actions in scene causes performance issues with SplineInstantiate components

Steps to reproduce:

1.  Add a bunch of spline instantiate component on GameObject with lots of elements
2. Do another action in the scene (such as selecting another GameObject)
3. Undo the action

Actual results: The SplineInstantiate components regenerate their content has it has not changed, causing huge performance drop.

Expected results: The SplineInstantiate components do not regenerate their content

Reproducible with versions: 2.9.0

Tested on (OS): Windows 11

Notes:

• From a discussion thread:
  https://discussions.unity.com/t/unity-splines-896343/896343/653