Bump actions/checkout from v2.3.3 to v2.3.4 (#639)

Bumps [actions/checkout](https://github.com/actions/checkout) from v2.3.3 to v2.3.4.
- [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/v2.3.3...5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/maven.yml

@@ -31,7 +31,7 @@ jobs:
             experimental: true        
         
     steps:
-    - uses: actions/checkout@v2.3.3
+    - uses: actions/checkout@v2.3.4
     - uses: actions/cache@v2
       with:
         path: ~/.m2/repository