remove random wait and set create test job parallel to 1

.github/workflows/create-test.yml

@@ -44,6 +44,7 @@ jobs:
   create-test:
     needs: setup
     strategy:
+      max-parallel: 1
       fail-fast: false
       matrix:
         region: [ us-east-1, us-west-2, ap-northeast-1, ap-southeast-1, eu-central-1 ]
@@ -62,7 +63,6 @@ jobs:
       - name: Create cluster
         run: |
           set +e
-          sleep $((RANDOM % 60))
           PROJECT_ID=1372813089447741295
           result=`ticloud cluster create -p  $PROJECT_ID --cluster-name ${{ matrix.region }} --cloud-provider AWS -r ${{ matrix.region }} --root-password ${{ secrets.TIDB_CLOUD_PASSWORD }} --cluster-type SERVERLESS`
           exitcode="$?"