build(deps): bump actions/checkout from 5 to 6 (#853)

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>
Co-authored-by: Pete Gadomski <[email protected]>

Author: dependabot[bot]

.github/workflows/continuous-integration.yml

@@ -25,7 +25,7 @@ jobs:
           - windows-latest
           - macos-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
         with:
           python-version: ${{ matrix.python-version }}
@@ -47,7 +47,7 @@ jobs:
     name: min-versions
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
         with:
           activate-environment: true
@@ -61,7 +61,7 @@ jobs:
     name: pre-release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
       - name: Sync
         run: uv sync
@@ -75,7 +75,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
       - name: Sync
         run: uv sync
@@ -91,7 +91,7 @@ jobs:
       run:
         shell: bash -el {0}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
       - name: Install pandoc
         run: sudo apt-get install -y pandoc

.github/workflows/release.yml

@@ -10,7 +10,7 @@ jobs:
     name: release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python 3.11
         uses: actions/setup-python@v6
         with: