Build/Test Tools: Use caching built into actions/setup-node.

This updates the `actions/setup-node` action to version 2.2.2 and takes advantage of the cache feature now built in. This removes the need for an additional step using `actions/cache` to cache NPM dependencies.

The cache key used will be `${{ runner.os }}-npm-${{ hashFiles('') }}`, which matches the recommendation in the `actions/cache` documentation and the key currently in use in the WordPress workflows.

Props gziolo.
Fixes #53584.

git-svn-id: https://develop.svn.wordpress.org/trunk@51341 602fd350-edb4-49c9-b593-d223f7449a82

.github/workflows/phpunit-tests.yml

@@ -43,7 +43,6 @@ jobs:
   # - Set environment variables.
   # - Sets up the environment variables needed for testing with memcached (if desired).
   # - Installs NodeJS 14.
-  # - Sets up caching for NPM.
   # - Installs NPM dependencies
   # - Configures caching for Composer.
   # - Installs Composer dependencies (if desired).
@@ -114,18 +113,10 @@ jobs:
         uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f # v2.3.4
 
       - name: Install NodeJS
-        uses: actions/setup-node@46071b5c7a2e0c34e49c3cb8a0e792e86e18d5ea # v2.1.5
+        uses: actions/setup-node@38d90ce44d5275ad62cc48384b3d8a58c500bb5f # v2.2.2
         with:
           node-version: 14
-
-      - name: Use cached Node modules
-        uses: actions/cache@26968a09c0ea4f3e233fdddbafd1166051a095f6 # v2.1.4
-        env:
-          cache-name: cache-node-modules
-        with:
-          # npm cache files are stored in `~/.npm` on Linux/macOS
-          path: ~/.npm
-          key: ${{ runner.os }}-npm-${{ hashFiles('**/package-lock.json') }}
+          cache: npm
 
       - name: Install Dependencies
         run: npm ci