Bump actions/checkout from 5 to 6 (#204)

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

Author: dependabot[bot]

.github/workflows/codeql-analysis.yml

@@ -39,7 +39,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL

.github/workflows/pypi.yml

@@ -8,7 +8,7 @@ jobs:
     name: "Build and publish release"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with:

.github/workflows/testing.yml

@@ -25,7 +25,7 @@ jobs:
       #       check-out repo and set-up python
       #----------------------------------------------
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup uv
         uses: astral-sh/setup-uv@v7
       - name: Setup Python