fix: delete user credentials stored in storages_credentials when user gets deleted

[yemkareems]

• Resolves: #

Summary

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[yemkareems]

/backport to stable29

[yemkareems]

/backport to stable28

[yemkareems]

/backport to stable27

[yemkareems]

/backport to stable26

[yemkareems]

/backport to stable25

[yemkareems]

/backport to stable24

[backportbot]

The backport to stable24 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable24
git pull origin stable24

# Create the new backport branch
git checkout -b backport/45355/stable24

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 7278198e

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/45355/stable24

Error: No changes found in backport branch

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.