Fix locking behaviour for fetching own user in OwnIDStore

[FasterSpeeding]

Summary

Checklist

• [ ] I have run nox and all the pipelines have passed.
• [ ] I have made unittests according to the code I have added/modified/deleted.

Related issues

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PR Preview Action ddfa7dc4b5f8fa02675fe5da02ae15c9722367f0 :---: Preview removed because the pull request was closed. 2024-07-26 21:33 UTC