build(deps): bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
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/flake-update.yml

@@ -13,7 +13,7 @@ jobs:
       machines: ${{ steps.gen_machines.outputs.machines }}
     steps:
       - name: Clone repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           token: "${{ secrets.GH_TOKEN }}"
           fetch-depth: 0

.github/workflows/package-update.yml

@@ -12,7 +12,7 @@ jobs:
       packages: ${{ steps.gen_packages.outputs.packages }}
     steps:
       - name: Clone repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           token: "${{ secrets.GH_TOKEN }}"
       - name: Install nix
@@ -38,7 +38,7 @@ jobs:
         package: ${{fromJson(needs.generate_matrix.outputs.packages)}}
     steps:
       - name: Clone repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           token: "${{ secrets.GH_TOKEN }}"
       - name: Install nix

.github/workflows/update-nixpkgs.yml

@@ -21,7 +21,7 @@ jobs:
     needs: [sync_fork]
     steps:
       - name: Clone repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: "Shawn8901/nixpkgs"
           token: "${{ secrets.GH_TOKEN }}"