chore(deps): update pnpm to v9 (#134)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -2,7 +2,7 @@
   "name": "@tresjs/post-processing",
   "type": "module",
   "version": "1.0.0-next.2",
-  "packageManager": "pnpm@8.10.2",
+  "packageManager": "pnpm@9.14.2",
   "description": "Post-processing library for TresJS",
   "author": "Alvaro Saburido <hola@alvarosaburido.dev> (https://github.com/alvarosabu/)",
   "license": "MIT",