github-actions(deps): bump actions/checkout from 2.3.5 to 2.4.0

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](actions/checkout@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] <[email protected]>

.github/workflows/ci-docs.yml

@@ -28,7 +28,7 @@ jobs:
 
     steps:
     - name: Checkout sources
-      uses: actions/checkout@v2.3.5
+      uses: actions/checkout@v2.4.0
       with:
         # need history and tags for versioneer
         fetch-depth: 0
@@ -92,7 +92,7 @@ jobs:
 
     steps:
     - name: Checkout docs
-      uses: actions/checkout@v2.3.5
+      uses: actions/checkout@v2.4.0
       with:
         ref: gh-pages
 

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
     - name: Checkout sources
-      uses: actions/checkout@v2.3.5
+      uses: actions/checkout@v2.4.0
       with:
         # need history and tags for versioneer
         fetch-depth: 0

.github/workflows/codeql-analysis.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v2.3.5
+      uses: actions/checkout@v2.4.0
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL