replace N1_HIGHCPU_8 with E2_HIGHCPU_8

update cloudbuild.yaml

Author: sepehrsoh

cloudbuild.yaml

@@ -2,7 +2,7 @@
 timeout: 2700s
 options:
   substitution_option: ALLOW_LOOSE
-  machineType: 'N1_HIGHCPU_8'
+  machineType: 'E2_HIGHCPU_8'
 steps:
   - name: 'gcr.io/k8s-staging-test-infra/gcb-docker-gcloud:v20220609-2e4c91eb7e'
     entrypoint: make