GH Actions: Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

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

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

.github/workflows/update-website.yml

@@ -73,7 +73,7 @@ jobs:
       # Retention is normally 90 days, but this artifact is only for review
       # and use in the next step, so no need to keep it for more than a day.
       - name: Upload the artifacts folder
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         if: ${{ success() }}
         with:
           name: website-updates