fix nightly performance tests and push metrics into pushgateway

.github/actions/performance-tests/art.yaml

@@ -1,5 +1,5 @@
 config:
-  target: "-=http_request_protocol=-://-=endpoint_to_test=-"
+  target: "http://localhost:9545"
   phases:
     - duration: 300
       arrivalRate: 400
@@ -14,6 +14,11 @@ config:
     ensure:
       - type: "failure"
         threshold: 1
+    publish-metrics:
+      - type: prometheus
+        pushgateway: 'https://pushgateway.dev-zetachain-internal.com'
+        tags:
+          - 'type:loadtest'
   summary: true
   reports:
     - type: "html"