build(deps): bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/checks.yml

@@ -8,7 +8,7 @@ jobs:
   checks:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: DeterminateSystems/nix-installer-action@main
     - uses: DeterminateSystems/magic-nix-cache-action@main
     - run: nix flake check -L --accept-flake-config --option sandbox false

.github/workflows/luarocks.yml

@@ -11,7 +11,7 @@ jobs:
     name: LuaRocks upload
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
       - name: Install Rust toolchain
         uses: actions-rust-lang/setup-rust-toolchain@v1
         with:

.github/workflows/nix-build.yml

@@ -15,7 +15,7 @@ jobs:
           - { os: macos-13, target: x86_64-darwin }
           - { os: macos-14, target: aarch64-darwin }
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: DeterminateSystems/nix-installer-action@main
     - uses: cachix/cachix-action@v15
       with:

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

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - uses: DeterminateSystems/nix-installer-action@v9
       - name: Update flake.lock
         uses: DeterminateSystems/update-flake-lock@v20