chore(github): 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-dev-shells.yml

@@ -31,7 +31,7 @@ jobs:
             os: macos-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Install Nix
         uses: cachix/install-nix-action@v31
         with:

.github/workflows/check.yml

@@ -7,7 +7,7 @@ jobs:
     name: Check flake
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Check Nix flake inputs
         uses: DeterminateSystems/flake-checker-action@v12
       - uses: cachix/install-nix-action@v31

.github/workflows/deadnix.yml

@@ -7,7 +7,7 @@ jobs:
     name: Deadnix
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable

.github/workflows/fmt.yml

@@ -7,7 +7,7 @@ jobs:
     name: Check expressions
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: cachix/install-nix-action@v31
         with:
           install_url: https://nixos.org/nix/install

.github/workflows/lint.yml

@@ -7,7 +7,7 @@ jobs:
     name: Lint code
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: cachix/install-nix-action@v31
         with:
           nix_path: nixpkgs=channel:nixos-unstable

.github/workflows/update-flakes.yml

@@ -35,7 +35,7 @@ jobs:
             echo "name=$name"
             echo "email=$id+$name@users.noreply.github.com"
           } >> "$GITHUB_OUTPUT"
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Setup Git
         env:
           GIT_USER_NAME: ${{ steps.user-info.outputs.name || 'github-actions[bot]' }}