Bump actions/checkout from v2.3.2 to v2.3.3

Bumps [actions/checkout](https://github.com/actions/checkout) from v2.3.2 to v2.3.3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2.3.2...a81bbbf8298c0fa03ea29cdc473d45769f953675)

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

.github/workflows/labels_sync.yaml

@@ -7,7 +7,7 @@ jobs:
     name: Sync labels
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2.3.2
+    - uses: actions/checkout@v2.3.3
     - uses: lannonbr/issue-label-manager-action@2.0.0
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}