build(deps): 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/build.yml

@@ -29,7 +29,7 @@ jobs:
 
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       with:
         submodules: recursive
     - name: Install dependencies

.github/workflows/nix.yml

@@ -18,7 +18,7 @@ jobs:
       matrix:
         os: [ubuntu]
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: cachix/install-nix-action@v31
       - uses: cachix/cachix-action@v17
         with:

.github/workflows/update-flake-lock.yml

@@ -18,7 +18,7 @@ jobs:
           app-id: ${{ secrets.MC_RTC_NIX_APP_ID }}
           private-key: ${{ secrets.MC_RTC_NIX_APP_PRIVATE_KEY }}
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           token: ${{ steps.app-token.outputs.token }}
       - name: Setup Nix