Bump actions/upload-artifact from 4 to 6 (#24)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  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/python.yaml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v6
       - run: python -m pip install -U build
       - run: python -m build --sdist
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v6
         with:
           name: sdist
           path: dist/*.tar.gz
@@ -29,7 +29,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: pypa/cibuildwheel@v3.2.0
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v6
         with:
           name: ${{ matrix.arch }}
           path: ./wheelhouse/*.whl