build(deps): bump actions/checkout from 3 to 4 (#9)

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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/docgen.yml

@@ -10,7 +10,7 @@ jobs:
     name: Generate docs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.0.2
+      - uses: actions/checkout@v4
       - uses: cachix/install-nix-action@v22
       - uses: cachix/cachix-action@v12
         with:

.github/workflows/flakehub-publish-tagged.yml

@@ -16,7 +16,7 @@ jobs:
       id-token: "write"
       contents: "read"
     steps:
-      - uses: "actions/checkout@v3"
+      - uses: "actions/checkout@v4"
         with:
           ref: "${{ (inputs.tag != null) && format('refs/tags/{0}', inputs.tag) || '' }}"
       - uses: "DeterminateSystems/nix-installer-action@main"

.github/workflows/nix-build.yml

@@ -6,6 +6,6 @@ jobs:
   checks:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: cachix/install-nix-action@v22
     - run: nix flake check -L

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     name: Release
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Luarocks Upload
         uses: nvim-neorocks/luarocks-tag-release@v5
         env: