fix: check that amplify is actually ready

.github/workflows/scripts/on-demand-env-script.sh

@@ -284,14 +284,19 @@ npm i
 # Build and run Docker images
 npm run dev &
 
-# Wait for graphql service to come up
-while ! nc -z localhost 20002; do
-  sleep 10
+# Believe it or not but this actually checks whether amplify is ready
+while true; do
+    AMPLIFY_READY=$(curl -X POST -H "x-api-key: da2-fakeApiId123456" -H "Content-Type: application/json" -d '{"query":"query { __schema { types { name } } }"}' -s http://localhost:20002/graphql | jq 'has("data")')
+
+    if [[ "$AMPLIFY_READY" == "true" ]]; then
+        echo "Amplify seems to be up. Going our merry way."
+        break
+    else
+        echo "Amplify is not up yet, waiting..."
+        sleep 5
+    fi
 done
 
-# Wait for amplify to be really done
-sleep 20
-
 # Seed database (pass --yes to skip confirmation)
 node ./scripts/create-data.js --yes