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] <support@github.com>

Author: dependabot[bot]

.github/workflows/builds.yml

@@ -63,7 +63,7 @@ jobs:
           pacman --noconfirm -Sy git || true
           echo "::endgroup::"
       - name: Repository checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install dependency packages
         run: .github/workflows/${{ env.DISTRO }}.sh
       - name: Enable ccache to speed up builds

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Repository checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install dependency packages
         run: sudo .github/workflows/ubuntu.sh