fix(polls): require edit permission for shifting date options

[hamza221]

Assisted-by: ClaudeCode:claude-opus-5

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI (N/A)

[hamza221]

/backport to stable-8

[hamza221]

/backport! to stable8.3

[backportbot]

The backport to stable8.3 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable8.3
git pull origin stable8.3

# Create the new backport branch
git checkout -b backport/5057/stable8.3

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 6d12db09

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/5057/stable8.3

Error: Failed to check for changes with origin/stable8.3: 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.

[dartcafe]

Please add the changelog entry under [Unreleased].