R1:b1a5d5a81548

Stop purging caches in bin/storage adjust

Summary:
Fixes T6548.

- This workflow doesn't work under reasonable configurations and isn't trivial to fix (see T6548).
- We don't need it; this just makes things a little bit faster if you have to migrate everything (e.g., immediately after T1191) and the installs we know about have generally upgraded by now.
- This keeps kicking PKCS8 keys out of cache which is a pain.

Test Plan: Ran `bin/storage adjust` without it doing an implicit cache purge.