Currently we have a cache for all combinations of "strand/strip" and
the four subdivision levels. Recomputing this data should be very fast
and doesn't require re-uploading data from the CPU. Because they are
scene settings, they will be the same for all render engines too, so we
won't have a case where we're constantly requesting different values.
The extra caches just complicate code, so better to remove them. Now
the final evaluated cache remembers the settings it was created with,
and it's cleared if they are changed.
Pull Request: https://projects.blender.org/blender/blender/pulls/119804
84c6ead74b