[stable29] fix: skip exporting a deleted card

[backportbot]

Backport of #6692

Warning, This backport's changes differ from the original and might be incomplete ⚠️

Todo

• Review and resolve any conflicts
• Amend HEAD commit to remove the line stating to skip CI

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

[github-actions]

🐢 Performance warning.
It looks like the query count of the integration tests increased with this PR.
Database query count is now 71827 was 69334 (+3.59%)
Please check your code again. If you added a new test this can be expected and the base value in tests/integration/base-query-count.txt can be increased.

[github-actions]

🐢 Performance warning.
It looks like the query count of the integration tests increased with this PR.
Database query count is now 71827 was 69334 (+3.59%)
Please check your code again. If you added a new test this can be expected and the base value in tests/integration/base-query-count.txt can be increased.

[elzody]

Cypress failure is not related. Also failing on stable29