Bump actions/checkout from 5 to 6 (#368)

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](https://github.com/actions/checkout/compare/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>

.github/workflows/build-python-packages.yml

@@ -86,7 +86,7 @@ jobs:
       ARTIFACT_NAME: python-${{ inputs.VERSION || '3.13.7' }}-${{ matrix.platform }}-${{ matrix.arch }}
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
       
@@ -113,7 +113,7 @@ jobs:
       ARTIFACT_NAME: python-${{ inputs.VERSION || '3.13.7' }}-${{ matrix.platform }}-${{ matrix.arch }}
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
 

.github/workflows/manifest-config-validation.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         submodules: true
 

.github/workflows/python-versions-runner.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out repository code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       
       - name: Trigger python workflow
         run: |