Put regression results into workflow summary even for not PRs

The Continuous Integration workflow runs on
- pushes
- pull requests
- a schedule
- workflow calls from database testing

With this change, we create the regression test summary and cat it into
the workflow summary for all job types,
though it is still only uploaded as an artifact
for pull requests.

.github/workflows/CI.yml

@@ -346,9 +346,9 @@ jobs:
           fi
 
       - name: Prepare Results for PR Comment
-        if : ${{ github.event_name == 'pull_request' }}
+        if: ${{ env.REFERENCE_JOB == 'false' }}
         env:
-          PR_NUMBER: ${{ github.event.number }}
+          PR_NUMBER: ${{ github.event.number || github.event.after || github.event_name }}
         run: |
           echo $PR_NUMBER > summary.txt
           echo "## Regression Testing Results" >> summary.txt