chore(deps): update pnpm to v9.15.9

Author: renovate[bot]

package.json

@@ -2,7 +2,7 @@
   "name": "the-guild-docs-monorepo",
   "type": "module",
   "private": true,
-  "packageManager": "[email protected].4",
+  "packageManager": "[email protected].9",
   "scripts": {
     "build": "turbo run build --filter=!website",
     "build-example": "turbo run build --filter=website",