feat: updated action to use cache v4

Author: jonnyAmplience

.github/workflows/app.yml

@@ -18,7 +18,7 @@ jobs:
         run: |
           echo "::set-output name=dir::$(npm config get cache)"
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v4
         with:
           path: ${{ steps.npm-cache.outputs.dir }}
           key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}