chore(deps): update pnpm to v9.1.4

Author: renovate[bot]

package.json

@@ -7,7 +7,7 @@
   "license": "MIT",
   "repository": "https://github.com/keystonejs/keystone",
   "homepage": "https://github.com/keystonejs/keystone",
-  "packageManager": "[email protected].3",
+  "packageManager": "[email protected].4",
   "scripts": {
     "coverage": "jest --coverage",
     "test": "jest",