Deps: Bump actions/upload-pages-artifact from 1 to 2

Bumps [actions/upload-pages-artifact](https:/actions/upload-pages-artifact) from 1 to 2.
- [Release notes](https:/actions/upload-pages-artifact/releases)
- [Commits](actions/upload-pages-artifact@v1...v2)

---
updated-dependencies:
- dependency-name: actions/upload-pages-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/github-pages.yml

@@ -38,7 +38,7 @@ jobs:
  run: |
  cd docs && poetry run make html
  - name: Upload artifact
- uses: actions/upload-pages-artifact@v1
+ uses: actions/upload-pages-artifact@v2
  with:
  path: "docs/_build/html"
  - name: Deploy to GitHub Pages