Bump actions/checkout from 5 to 6 (#455)

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

Author: dependabot[bot]

.github/workflows/check.yaml

@@ -35,7 +35,7 @@ jobs:
           - { os: windows-2025, py: pypy3.11 }
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: "🔄 Install the latest version of uv"
@@ -80,7 +80,7 @@ jobs:
     runs-on: ubuntu-24.04
     needs: test
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: "🔄 Install the latest version of uv"
@@ -126,7 +126,7 @@ jobs:
         exclude:
           - { os: windows-2025, tox_env: pkg_meta }
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: "🔄 Install the latest version of uv"

.github/workflows/release.yaml

@@ -10,7 +10,7 @@ jobs:
   build:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: "🔄 Install the latest version of uv"