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](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
...

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

.github/workflows/build-user-config.yml

@@ -33,7 +33,7 @@ jobs:
       has_valid_build_matrix: ${{ steps.fetch.outputs.has_valid_build_matrix }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Fetch Build Matrix
         id: fetch
@@ -67,7 +67,7 @@ jobs:
           curl -fsSL https://deb.nodesource.com/setup_22.x | bash && apt install -y nodejs
 
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Create build directory
         run: |