Fix pnpm setup conflict with packageManager pin

Author: gildesmarais

.github/workflows/ci.yml

@@ -60,7 +60,6 @@ jobs:
           version: 10
           cache: true
           cache_dependency_path: frontend/pnpm-lock.yaml
-          package_json_file: frontend/package.json
 
       - name: Setup Node.js for OpenAPI lint tooling
         uses: actions/setup-node@v6
@@ -91,7 +90,6 @@ jobs:
           version: 10
           cache: true
           cache_dependency_path: frontend/pnpm-lock.yaml
-          package_json_file: frontend/package.json
 
       - name: Setup Node.js
         uses: actions/setup-node@v6
@@ -196,7 +194,6 @@ jobs:
           version: 10
           cache: true
           cache_dependency_path: frontend/pnpm-lock.yaml
-          package_json_file: frontend/package.json
 
       - name: Setup Node.js for Docker build
         uses: actions/setup-node@v6