Set pnpm version as 9 (#184)

Author: whitphx

.github/workflows/main.yml

@@ -113,7 +113,7 @@ jobs:
 
       - uses: pnpm/action-setup@v4
         with:
-          version: 6.0.2
+          version: 9
           run_install: |
             cwd: pyodide-e2e