build(deps): bump actions/checkout from 2 to 2.3.4 (#405)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 2.3.4.
- [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...v2.3.4)

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

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

.github/workflows/code-samples.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       - name: Gradle Wrapper Validation
         uses: gradle/wrapper-validation-action@v1.0.3
 
@@ -47,7 +47,7 @@ jobs:
       image: gradle:jdk8
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       - name: Setup Cache
         uses: actions/cache@v2.1.5
         with:

.github/workflows/docs.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
       - name: Get Plugin Verifier Version
         id: get-version
         run: |