[FIX] "Export Messages" only works for global roles

[pierre-lehnen-rc]

Proposed changes

Issue(s)

Closes #19262

How to test or reproduce

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Hotfix (a major bugfix that has to be merged asap)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules

Changelog

Further comments

[Gummikavalier]

Now regarding that after moving to 3.8.0 users would be capable of exporting complete channels with all their attachments: Is there a risk that auto pruning does not clear up the export files in GridFS / Database automatically, leading to very high storage use when users adopt it?

I did not find any documentation or admin features about clearing up those particularly.