sets up prod push to use npm caching

.github/workflows/prod_push_to_s3.yml

@@ -14,16 +14,23 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Use Node.js 14.x
-      uses: actions/setup-node@v1
+    - uses: actions/checkout@v3
+
+    - name: Use Node.js 16.x
+      uses: actions/setup-node@v3
       with:
-        node-version: '14.x'
+        node-version: '16.x'
+        cache: 'npm'
+
+    - name: install npm 6
+      run: |
+        npm install -g npm@6
 
     - name: npm install, and build
       run: |
         printf "@fortawesome:registry=https://npm.fontawesome.com/\n//npm.fontawesome.com/:_authToken=${FONTAWESOME_NPM_AUTH_TOKEN}" >> ~/.npmrc
-        npm install
+        git config --global url."https://".insteadOf ssh://
+        npm ci
         npm run build:production
       env:
         FONTAWESOME_NPM_AUTH_TOKEN: ${{ secrets.FA_AUTH_TOKEN }}