ci: update node version to 16 (#911)

Author: Oreoxmt

.github/workflows/ci.yaml

@@ -8,10 +8,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Check out
-      uses: actions/checkout@v2
-    - uses: actions/setup-node@v1
+      uses: actions/checkout@v3
+    - uses: actions/setup-node@v3
       with:
-        node-version: '12'
+        node-version: '16'
     - name: "Check file encoding"
       run:
         git remote add upstream https://github.com/pingcap/docs-dm.git;