chore: prevent the pr actions from filing on merge_group

I _believe_ I can remove this in order to prevent the check from failing
on merges. I'm not sure if this is required in order for the merge group
to pass required checks though 🤔

Signed-off-by: R. Tyler Croy <[email protected]>

Author: rtyler

.github/workflows/dev_pr.yml

@@ -2,7 +2,6 @@ name: dev_pr
 
 # Trigger whenever a PR is changed (title as well as new / changed commits)
 on:
-  merge_group:
   pull_request_target:
     types:
       - opened