test: pass GATEWAY_COMMIT when building gateway container

Author: neithanmo

setup-test-network.sh

@@ -354,7 +354,7 @@ sleep 10 # Give indexer time to process initial blocks
 
 echo "Building gateway image..."
 source local-network/.env
-docker build -t local-gateway:latest ./local-network/gateway
+docker compose -f local-network/docker-compose.yaml build gateway
 
 echo "Running gateway container..."
 # Verify required files exist before starting gateway