Bump actions/checkout from 5.0.0 to 6.0.0 in the all group

Bumps the all group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 5.0.0 to 6.0.0
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@08c6903...1af3b93)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all
...

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

Author: dependabot[bot]

.github/workflows/validate.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     name: "Validate landscape.yml file"
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       - uses: cncf/landscape2-validate-action@6381e8747c73412e638670807b402ef2b863e9f8 # v2.0.1
         with:
           target_kind: data