build: fix quoting

Author: kgryte

.github/workflows/lint_pr_title.yml

@@ -87,5 +87,5 @@ jobs:
         run: |
           echo "Pull request titles should follow stdlib's Git commit message conventions."
           echo "Linting pull request title..."
-          make lint-commit-message GIT_COMMIT_MESSAGE="'${{ github.event.pull_request.title }}'"
+          make lint-commit-message GIT_COMMIT_MESSAGE='${{ github.event.pull_request.title }}'
         timeout-minutes: 5