Point Caches (used by particle system, cloth, boids etc.) are now
always compressed, uzing zstd coupled with lossless data filtering.
- This is both smaller cache files _and_ faster than the old
"Heavy" compression mode,
- And smaller data files and same or slightly faster speed than
using no compression at all,
- There was not much difference between compression levels once
data filtering got added, so option to pick them was removed.
- So there's no downside to just always using the compression,
which makes for a simpler UI.
- RNA change: removes PointCache.compression property.
More details and cache size / performance numbers in the PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/144356