Bump actions/checkout from 6.0.2 to 7.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 6.0.2 to 7.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@de0fac2...9c091bb)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 7.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/validate-pr.yml

@@ -21,13 +21,13 @@ jobs:
           exclude-statuses: 'removed'
 
       - name: Checkout repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # pin@v6.0.2
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # pin@v7.0.0
         with:
           ref: ${{ github.event.pull_request.head.ref }}
           repository: ${{ github.event.pull_request.head.repo.full_name }}
 
       - name: Checkout upstream
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # pin@v6.0.2
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # pin@v7.0.0
         with:
           path: upstream
           ref: main