Bump actions/checkout from v2.3.3 to v2.3.4 (#2152)

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/build.yml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v2.3.3
+      - uses: actions/checkout@v2.3.4
         with:
           submodules: true
 

.github/workflows/check-formatting.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-    - uses: actions/checkout@v2.3.3
+    - uses: actions/checkout@v2.3.4
     - name: apt-get update
       run: sudo apt-get update