chore: remove deprecated web-renderer option to fix broken web builds

Author: w568w

.github/workflows/deploy_to_gh-pages.yml

@@ -26,7 +26,7 @@ jobs:
 
       - name: Build
         run: |
-          flutter build web --release --web-renderer html
+          flutter build web --release --optimization-level 4
 
       - name: Deploy 🚀
         uses: JamesIves/github-pages-deploy-action@v4.2.5