chore: set pnpm version for github action

Author: jerzy-mankowski

.github/workflows/pull-request.yml

@@ -14,6 +14,8 @@ jobs:
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
+        with:
+          version: 9
 
       - name: Use Node.js
         uses: actions/setup-node@v4