chore(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...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/codeql.yml

@@ -29,7 +29,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4

.github/workflows/python-cd.yml

@@ -20,7 +20,7 @@ jobs:
       packages: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6.0.2
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/python-ci.yml

@@ -16,7 +16,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6.0.2
+        uses: actions/checkout@v6
 
       - name: Lint commit messages
         uses: wagoid/commitlint-github-action@v6.2.1
@@ -51,7 +51,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6.0.2
+        uses: actions/checkout@v6
 
       - name: Set up uv
         uses: astral-sh/setup-uv@v7.5.0
@@ -92,7 +92,7 @@ jobs:
     if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name == github.repository
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6.0.2
+        uses: actions/checkout@v6
 
       - name: Download coverage report artifact
         uses: actions/download-artifact@v8.0.1