fix yaml lint

Author: sebsto

.github/workflows/pull_request.yml

@@ -40,4 +40,5 @@ jobs:
         with:
           persist-credentials: false
       - name: Check for Semantic Version label
-        uses: apple/swift-nio/.github/actions/pull_request_semver_label_checker@main
+        uses: apple/swift-nio/.github/actions/pull_request_semver_label_checker@main
+