Remove action.jelly

[janfaracik]

As far as I can tell, these files aren't used/visible in the interface - seeing as a lot of the pages are 'one-column' I'm not sure where'd they'd appear.

Testing done

• Interface still functional
• Breadcrumbs still work

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[jglick]

Not sure. Might have been unused for years. I cannot find anything missing in the UI from this either.