Change git push reference in dependabot workflow

Update the git push command to use github.head_ref.

Author: mamico

.github/workflows/dependabot.yml

@@ -44,6 +44,7 @@ jobs:
           git config --global user.name "RedTurtle CI BOT"
           git add dependabot/requirements.txt sbom.spdx.json
           git commit -m "Auto-generate file at $(date)" || exit 0
-          git push https://${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:${{ github.ref_name }}
+          # git push https://${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:${{ github.ref_name }}
+          git push https://${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git HEAD:${{ github.head_ref }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}