Update actions/upload-pages-artifact action to v4 (#82)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/static.yml

@@ -43,7 +43,7 @@ jobs:
           mkdir -p pages
           ./tools/gendocs.sh > pages/index.html
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         with:
           path: 'pages'
       - name: Deploy to GitHub Pages