feat(sdk): Loop over and delete all backup versions on identity reset

[kaylendog]

This PR adjusts the identity reset logic to loop on GET /_matrix/client/v3/room_keys/version, deleting all backups until none remain.

When we reset our identity, we delete the current backup version, but not any other versions if they happen to exist. This can leave clients in a broken state where they are unable to enable key backup since one already exists server-side. Deleting all backup versions on reset should fix this issue.

• I've documented the public API changes in the appropriate changelog files (see Writing changelog entries).
• This PR was made with the help of AI.

Signed-off-by: Skye Elliot actuallyori@gmail.com

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.89%. Comparing base (390f6c0) to head (b461727).
⚠️ Report is 9 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/matrix-sdk/src/encryption/backups/mod.rs	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6744      +/-   ##
==========================================
- Coverage   89.91%   89.89%   -0.02%     
==========================================
  Files         398      398              
  Lines      111310   111308       -2     
  Branches   111310   111308       -2     
==========================================
- Hits       100083   100062      -21     
- Misses       7420     7437      +17     
- Partials     3807     3809       +2     

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[codspeed-hq]

Merging this PR will not alter performance

✅ 50 untouched benchmarks

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_{Comparing kaylendog/backups/loop-delete (b461727) with main (afc182e)}

[uhoreg]

Looks reasonable, but a couple of nits.

[uhoreg]

The doc comment needs updating too

[kaylendog]

Addressed in b461727

[uhoreg]

The change affects more than just resetting. It also affects recover_and_fix_backup and, of course, direct calls to disable_and_delete. If you don't want to list them all, maybe something like "Functions that delete key backups, such as resetting your cryptographic identity, ..."?

[kaylendog]

Addressed in b461727