Bump actions/checkout from 5 to 6 (#559)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
       version: ${{ steps.version.outputs.version }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Setup Python
       uses: actions/setup-python@v6
     - name: Cache PyPI
@@ -54,7 +54,7 @@ jobs:
     timeout-minutes: 10
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Setup Python ${{ matrix.python-version }}
       uses: actions/setup-python@v6
       with:
@@ -110,7 +110,7 @@ jobs:
     if: github.event_name == 'push' && contains(github.ref, 'refs/tags/')
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Setup Python
       uses: actions/setup-python@v6
     - name: Install dependencies

.github/workflows/codeql.yml

@@ -24,7 +24,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4