build(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] <[email protected]>

Author: dependabot[bot]

.github/workflows/containers.yml

@@ -20,7 +20,7 @@ jobs:
         baseimage: ['debian:bullseye', 'debian:trixie', 'ubuntu:20.04', 'ubuntu:24.04', 'fedora']
         go: [1.23, 1.24, 1.25]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Run tests in container
         run: ./scripts/ci-runner.sh run_in_ct ${{ matrix.baseimage }} ${{ matrix.go }}
 

.github/workflows/go.yml

@@ -19,7 +19,7 @@ jobs:
       - run: sudo apt-get -qq update
       - name: Install libsystemd-dev
         run: sudo apt-get install libsystemd-dev
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Setup go
         uses: actions/setup-go@v6
         with:
@@ -35,7 +35,7 @@ jobs:
         run: |
           sudo apt-get -qq update
           sudo apt-get -qq install libsystemd-dev
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-go@v6
         with:
           go-version: stable