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] <support@github.com>

Author: dependabot[bot]

.github/workflows/autofix.yml

@@ -12,7 +12,7 @@ jobs:
     name: Regenerate autogenerated files
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - run: make codespell_lib/data/dictionary_en_to_en-OX_AUTOGENERATED.txt

.github/workflows/codespell.yml

@@ -9,7 +9,7 @@ jobs:
     name: Check for spelling errors
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: codespell-project/actions-codespell@master

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
   package:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Set up Python

.github/workflows/tests.yml

@@ -39,7 +39,7 @@ jobs:
             os: "windows-latest"
     name: "${{ matrix.python-version }} ${{ matrix.kind }} ${{ matrix.os }}"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Setup python
@@ -81,7 +81,7 @@ jobs:
     steps:
       - name: Setup Python
         uses: actions/setup-python@v6
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Install general dependencies