.github/workflows/pr-checklist.yml: Update

This newer version of the action does not fail mysteriously if a contributer
removes the example Jenkins commands from the end of the PR description.

Signed-off-by: Zack Cerza <[email protected]>

Author: zmc

.github/workflows/pr-checklist.yml

@@ -16,4 +16,4 @@ jobs:
         shell: bash
       - name: Action
         id: checklist
-        uses: ceph/ceph-pr-checklist-action@32e92d1a2a7c9991ed51de5fccb2296551373d60
+        uses: ceph/ceph-pr-checklist-action@b15031f5d7e2a825b7e5b2fd4f76ae3a9e8aaaf3