Don't label PRs again after /update-commit (#2284)

Signed-off-by: David Festal <dfestal@redhat.com>

Author: davidfestal

.github/workflows/update-plugins-repo-refs.yaml

@@ -210,6 +210,7 @@ jobs:
     needs: [update-branches, update-main-branch]
     if: |
       always() && 
+      inputs.pr-to-update == '' &&
       (needs.update-branches.result != 'skipped' ||  
        needs.update-main-branch.result != 'skipped')
     uses: ./.github/workflows/label-mandatory-workspace-prs.yaml