chore: setting pnpm version in engines

Author: gnomadic

package.json

@@ -4,7 +4,8 @@
   "license": "AGPL-3.0-only",
   "engines": {
     "npm": ">=8.5.5",
-    "node": ">=16.15.0"
+    "node": ">=16.15.0",
+    "pnpm": ">=9.3.0"
   },
   "scripts": {
     "start": "pnpm --filter round-manager run start",