This will work for other UI actions as well afaik
Spent hours trying to find out how to stop this UI action from showing on the HR Agent Worspace form so I thought I'd share here.
1. Go to UI Builder within the Agent Workspace for HR Case Management Application
2. Go to the HR Agent Workspace experience
3. Scroll down to the Case page
4. Select the 'Action bar' widget on the top right of the editor pane
5.Then the config bar on the right will update, select 'Manage declaritive action configuration' from the very bottom of the list
6. Amend the filter of that show to show all or action label starts with report
7. Open the record, make it inactive and Save
DONE
