Bump actions/upload-artifact from 5 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5...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>

Author: dependabot[bot]

.github/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
       env:
         BUILD_EXTENSION: no
     - name: Save sdist & wheel
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: dist-architecture-independent
         path: |
@@ -57,7 +57,7 @@ jobs:
       env:
         BUILD_EXTENSION: yes
     - name: Save wheels
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: dist-${{ matrix.os }}
         path: wheelhouse/*.whl