build(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...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>

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
     outputs:
       uncached: ${{ steps.get-packages.outputs.packages }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: "Install Nix"
         uses: cachix/install-nix-action@v31.8.2
 

.github/workflows/nix.yml

@@ -18,7 +18,7 @@ jobs:
   nix:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: "Install Nix"
         uses: cachix/install-nix-action@v31.8.2

.github/workflows/update-flake.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           token: "${{ secrets.GH_TOKEN}}"
 

.github/workflows/update-pkgs.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           token: "${{ secrets.GH_TOKEN}}"