chore: update pnpm action setup

.github/workflows/backend-ci.yml

@@ -33,7 +33,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Setup pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
         with:
           version: 9
       - name: Setup Node.js

.github/workflows/release.yml

@@ -58,7 +58,7 @@ jobs:
         uses: actions/checkout@v6
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
         with:
           version: 9
 

.github/workflows/security-scan.yml

@@ -35,7 +35,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Set up pnpm
-        uses: pnpm/action-setup@v4
+        uses: pnpm/action-setup@v6
         with:
           version: 9
       - name: Set up Node.js