Update actions/checkout requirement to v2.3.4

Updates the requirements on [actions/checkout](https://github.com/actions/checkout) to permit the latest version.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/commits/5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/labeler.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the repository
-        uses: actions/checkout@v2.3.3
+        uses: actions/checkout@v2.3.4
 
       - name: Run Labeler
         uses: crazy-max/ghaction-github-labeler@v3.1.1