Downgrade pnpm version to 9 in workflow and package.json

.github/workflows/nuxthub.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Install pnpm
         uses: pnpm/action-setup@v4
         with:
-          version: 10
+          version: 9
 
       - name: Install Node.js
         uses: actions/setup-node@v4

package.json

@@ -1,7 +1,7 @@
 {
   "name": "artsite",
   "private": true,
-  "packageManager": "pnpm@10.8.1",
+  "packageManager": "pnpm@9.8.0",
   "scripts": {
     "build": "nuxt build",
     "dev": "nuxt dev --host",