.github/workflows: bug fix: wrong version for issue-labeler

Author: hajimehoshi

.github/workflows/issue-labeler.yml

@@ -7,7 +7,7 @@ jobs:
   triage:
     runs-on: ubuntu-latest
     steps:
-    - uses: github/issue-labeler@v3
+    - uses: github/issue-labeler@v3.4
       with:
         repo-token: "${{ secrets.GITHUB_TOKEN }}"
         configuration-path: .github/workflows/issue-labeler/config.yml