fix: correct pnpm setup in GitHub Actions

- Use pnpm/action-setup@v2 instead of npm install -g
- Add proper pnpm cache configuration
- Fix 'Unable to locate executable file: pnpm' error

.github/workflows/release.yml

@@ -44,11 +44,25 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: '20'
-          cache: 'pnpm'
-          cache-dependency-path: frontend/pnpm-lock.yaml
 
       - name: Install pnpm
-        run: npm install -g pnpm
+        uses: pnpm/action-setup@v2
+        with:
+          version: 8
+
+      - name: Get pnpm store directory
+        id: pnpm-cache
+        shell: bash
+        run: |
+          echo "STORE_PATH=$(pnpm store path)" >> $GITHUB_OUTPUT
+
+      - name: Setup pnpm cache
+        uses: actions/cache@v3
+        with:
+          path: ${{ steps.pnpm-cache.outputs.STORE_PATH }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-pnpm-store-
 
       - name: Print build info
         run: |