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] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -47,7 +47,7 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }} # required
       - name: Archive code coverage results
         if: matrix.python-version == '3.12'
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: code-coverage-report
           path: coverage.xml

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
     - name: Build distribution 📦
       run: uv build
     - name: Store the distribution packages
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: python-package-distributions
         path: dist/