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

@@ -17,7 +17,7 @@ jobs:
         run: python -m pip install --upgrade pip build wheel twine readme-renderer
       - run: python -m build --sdist --wheel
       - run: python -m twine check dist/*
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v6
         with:
           path: dist/*
   docs:

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
       - run: sudo apt-get update && sudo apt-get install -y gettext
       - run: python -m pip install --upgrade pip build wheel
       - run: python -m build --sdist --wheel
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v6
         with:
           name: release-dists
           path: dist/