build(deps): bump actions/checkout from 2.3.5 to 2.4.0 (#584)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.3.5 to 2.4.0.
- [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/v2.3.5...v2.4.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: Gradle Wrapper Validation
         uses: gradle/wrapper-validation-action@v1.0.4
 
@@ -50,7 +50,7 @@ jobs:
           - tree_structure_provider
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: Setup Java
         uses: actions/setup-java@v2
         with:

.github/workflows/dependabot-combine-prs.yml

@@ -99,7 +99,7 @@ jobs:
             console.log('Combined: ' + combined);
             return combined
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2.3.5
+      - uses: actions/checkout@v2.4.0
         with:
           fetch-depth: 0
       # Creates a branch with other PR branches merged together

.github/workflows/docs.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: Get Plugin Verifier Version
         id: get-version
         run: |