Two issues:
- The `AS_asset_libraries_available()` function would always return
true, because `AssetLibraryService::get()` would actually allocate the
service if not available.
- The issue would still happen if another code path would call
`AssetLibraryService::get()` after the service was destroyed, and
before the UI data was destroyed. This was happening now, so the crash
was back, see #124167.
I'm working on a new fix, for now, remove this broken one.
fba6e050c2