build(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/code.yml

@@ -25,7 +25,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           submodules: recursive

.github/workflows/push-code.yml

@@ -19,7 +19,7 @@ jobs:
       contents: write
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: ♻️ Prepare
         run: |
           command mkdir -p gh-pages/code gh-pages/zsh