fix(filesreport): cast fileId to integer

[miaulalala]

• 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)

[miaulalala]

/backport to stable30

[miaulalala]

/backport to stable29

[miaulalala]

/backport to stable28

[backportbot]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28
# Create the new backport branch
git checkout -b backport/48031/stable28
# Cherry pick the change from the commit sha1 of the change against the default branch# This might cause conflicts, resolve them
git cherry-pick 35969bfa
# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/48031/stable28

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.