Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
       matrix:
         os: [ubuntu-20.04, ubuntu-22.04, macos-latest, windows-latest]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - uses: msys2/setup-msys2@v2
       if: ${{ runner.os == 'Windows' }}

.github/workflows/generate-docs.yml

@@ -15,7 +15,7 @@ jobs:
         shell: bash
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Install dependencies
         run: |