remove unused storage classes

[atravitz]

remove these unused storage classes, which will be replaced by warehouse in #2113

I'm not sure if this warrants a changelog entry, since we never exposed these in the docs. thoughts @IAlibay ?

LLM / AI generated code disclosure

LLMs or other AI-powered tools (beyond simple IDE use cases) were used in this contribution: no

Checklist

• All new code is appropriately documented (user-facing code must have complete docstrings).
• Added a news entry, or the changes are not user-facing.
• Ran pre-commit: you can run pre-commit locally or comment on this PR with pre-commit.ci autofix.
• Filled in the AI generated code disclosure.

Manual Tests: these are slow so don't need to be run every commit, only before merging and when relevant changes are made (generally at reviewer-discretion).

• GPU integration tests: running here
• example notebook testing: running here
• packaging tests: running here

Developers certificate of origin

• I certify that this contribution is covered by the MIT License here and the Developer Certificate of Origin at https://developercertificate.org/.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.28%. Comparing base (110503a) to head (a246670).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2169      +/-   ##
==========================================
- Coverage   95.20%   90.28%   -4.92%     
==========================================
  Files         213      206       -7     
  Lines       21138    20514     -624     
==========================================
- Hits        20124    18521    -1603     
- Misses       1014     1993     +979     

Flag	Coverage Δ
fast-tests	90.28% <ø> (?)
slow-tests	?

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