update action v2

Author: AlinsRan

.github/workflows/e2e-test-k8s.yml

@@ -22,6 +22,7 @@ on:
     branches:
       - master
       - release-v2-dev
+      - ci/k8s-1-18
   pull_request:
     branches:
       - master
@@ -37,7 +38,7 @@ jobs:
     runs-on: buildjet-2vcpu-ubuntu-1804
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v2
 
       - name: Setup Go Env
         id: go