chore(deps): Bump actions/checkout from 5 to 6

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] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -17,7 +17,7 @@ jobs:
       build_matrix: ${{ steps.set-build-matrix.outputs.build_matrix }}
     steps:
       - name: Source checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: 'Setup yq'
         uses: dcarbone/install-yq-action@v1.3.1
@@ -38,7 +38,7 @@ jobs:
       matrix: ${{ fromJson(needs.setup-matrix.outputs.build_matrix) }}
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Build image
         uses: docker/build-push-action@v6
@@ -53,7 +53,7 @@ jobs:
             RUBYGEM_OPENBOLT=${{ matrix.rubygem_openbolt }}
 
       - name: Clone voxpupuli/puppet-example repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: voxpupuli/puppet-example