fix(ci): update cache paths to use root package-lock.json for monorepo

Author: Abidoyesimze

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
         with:
           node-version: '20'
           cache: 'npm'
-          cache-dependency-path: frontend/package-lock.json
+          cache-dependency-path: package-lock.json
 
       - name: Install dependencies
         run: npm ci
@@ -62,7 +62,7 @@ jobs:
         with:
           node-version: '20'
           cache: 'npm'
-          cache-dependency-path: backend/package-lock.json
+          cache-dependency-path: package-lock.json
 
       - name: Install dependencies
         run: npm ci