Update pnpm version to use v9 (#11)

Author: javinchua

.github/workflows/main.yaml

@@ -28,7 +28,7 @@ jobs:
       - name: Install pnpm
         uses: pnpm/action-setup@v4
         with:
-          version: 8
+          version: 9
           run_install: false
 
       - name: Get pnpm store directory
@@ -71,7 +71,7 @@ jobs:
       - name: Install pnpm
         uses: pnpm/action-setup@v4
         with:
-          version: 8
+          version: 9
           run_install: false
 
       - name: Get pnpm store directory