ci: bump actions/checkout from 5 to 6 in the actions group

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


Updates `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](https://github.com/actions/checkout/compare/v5...v6)

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

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

.github/workflows/response.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout script
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           sparse-checkout: .github/scripts/close_unresponsive.js
           sparse-checkout-cone-mode: false
@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout script
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           sparse-checkout: .github/scripts/remove_response_label.js
           sparse-checkout-cone-mode: false