ci: use actions/checkout@v3 and runs on ubuntu-20.04

.github/workflows/test.yml

@@ -10,18 +10,18 @@ permissions:
 
 jobs:
   build: # make sure build/ci work properly
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/setup-node@v3
         with:
           node-version: 16
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - run: npm ci
       - run: npm run all
   test: # make sure the action works on a clean machine without building
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Create a simple Web site
         run: mkdir -p deploy_dist && echo -e "<pre>$(date -u)\n$GITHUB_SHA\n$GITHUB_REF</pre>" > deploy_dist/index.html
       - uses: ./