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](actions/checkout@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>

Author: dependabot[bot]

.github/workflows/c-cpp.yml

@@ -28,7 +28,7 @@ jobs:
       VCPKG_ROOT: ${{ github.workspace }}/vcpkg
 
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       with:
         submodules: true
 

.github/workflows/format.yml

@@ -9,7 +9,7 @@ jobs:
     name: Check formatting
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
       - name: Run clang-format style check for C/C++/Protobuf programs.
         uses: jidicula/clang-format-action@v4.18.0