build(deps): bump actions/upload-pages-artifact from 2 to 3

Bumps [actions/upload-pages-artifact](https://github.com/actions/upload-pages-artifact) from 2 to 3.
- [Release notes](https://github.com/actions/upload-pages-artifact/releases)
- [Commits](actions/upload-pages-artifact@v2...v3)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/doc.yml

@@ -45,7 +45,7 @@ jobs:
           make -C demo
           cp -r demo/static _site/demo
       - name: Upload pages
-        uses: actions/upload-pages-artifact@v2
+        uses: actions/upload-pages-artifact@v3
 
   publish:
     name: Publish website