ci(workflow): add 'npm' cache for actions/setup-node in .github/workflows

.github/workflows/build-test.yml

@@ -3,14 +3,14 @@ name: build-test
 on:
   pull_request:
     paths-ignore:
-      - '**.md'    
-  push:    
+      - "**.md"
+  push:
     branches:
       - main
       - releases/*
     paths-ignore:
-      - '**.md'
-      
+      - "**.md"
+
 jobs:
   build:
     runs-on: ${{ matrix.os }}
@@ -23,6 +23,7 @@ jobs:
         uses: actions/setup-node@v2
         with:
           node-version: 12.x
+          cache: npm
       - run: npm ci
       - run: npm run build
       - run: npm run format-check