Build(deps): Bump actions/checkout from 3.6.0 to 4.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.6.0 to 4.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3.6.0...v4.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/check.yml

@@ -13,14 +13,14 @@ jobs:
   license:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
       - name: Check License Lines
         uses: kt3k/[email protected]
   dco-check:
     runs-on: ubuntu-latest
     if: github.event_name == 'pull_request'
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
         with:
           fetch-depth: 0
       - name: Setup Python

.github/workflows/flake-update.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
       - name: Install Nix
         uses: cachix/install-nix-action@v23
         with: