Resolve "Dangerbot did not pick up removal of metrics"

What does this MR do and why?

If metric definition files are deleted entirely Dangerbot doesn't flag a MR as needing a Product Intelligence review.

Example: !112575 (comment 1297812641)

This MR changes the Dangerbot check to also flag deleted or renamed files for a Product Intelligence review.

To verify the new rule please see these two MRs targeting this branch:

• Deletion: !117387 (closed)
• Rename: !117401 (closed)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #393617 (closed)