chore(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](actions/checkout@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] <[email protected]>

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -25,7 +25,7 @@ jobs:
       packages: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 200
           fetch-tags: true

.github/workflows/pixi-lock.yml

@@ -12,7 +12,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout pull request
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/test.yml

@@ -45,7 +45,7 @@ jobs:
       DEPENDS: ${{ matrix.dependencies }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
           fetch-depth: 0
@@ -88,7 +88,7 @@ jobs:
         check: ["style", "spellcheck"]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install the latest version of uv