5f439c8e18
After 9e4c26574a, `relations_invalidate_cache()` for sound strips
returns without doing anything, but VSE code relied on this function to
tag scene to update `ID_RECALC_SEQUENCER_STRIPS` which is mostly audio
related. Since the name of this enum value is not very descriptive,
clarifying comment was added.
Pull Request: https://projects.blender.org/blender/blender/pulls/139991