chore(ci): add sleep 180

Signed-off-by: mlycore <maxwell92@126.com>
diff --git a/.github/workflows/proxy-integration.yml b/.github/workflows/proxy-integration.yml
index 31adc39..920e9f4 100644
--- a/.github/workflows/proxy-integration.yml
+++ b/.github/workflows/proxy-integration.yml
@@ -47,7 +47,7 @@
           kubectl get pod,svc -n ${TEST_NAMESPACE} --show-labels
           cd ..
           kubectl apply -f hack/kubernetes/mysql.yml
-          sleep180
+          sleep 180
           kubectl get pod,svc -n default --show-labels
           kubectl wait --timeout=120s --for=condition=Ready --all pod -n ${TEST_NAMESPACE}
           kubectl get pod,svc -n default --show-labels