Bump actions/checkout from 6 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [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/v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/build.yml

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1951296..ae794ec 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -96,7 +96,7 @@
     runs-on: ${{ matrix.os }}
     steps:
     - name: Clone tinycbor
-      uses: actions/checkout@v6
+      uses: actions/checkout@v7
 
     - name: install Linux software
       if: matrix.os == 'ubuntu-latest'