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/coverage_badge.yml

@@ -14,7 +14,7 @@ jobs:
       # added or changed files to the repository.
       contents: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.head_ref }}
       - uses: actions/setup-python@v6

.github/workflows/mypy.yml

@@ -20,7 +20,7 @@ jobs:
         python-version: ["3.9", "3.10", "3.11", "3.x"]
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with:

.github/workflows/publish.yml

@@ -9,7 +9,7 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.x"

.github/workflows/pylint.yml

@@ -16,7 +16,7 @@ jobs:
     name: Pylint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.x"

.github/workflows/pytest.yml

@@ -21,7 +21,7 @@ jobs:
         python-version: ["3.9", "3.10", "3.11", "3.x"]
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with: