chore(deps): update pnpm to v9.15.0 (#1859)

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

Author: renovate[bot]

package.json

@@ -2,7 +2,7 @@
   "name": "the-guild-docs-monorepo",
   "type": "module",
   "private": true,
-  "packageManager": "pnpm@9.14.4",
+  "packageManager": "pnpm@9.15.0",
   "scripts": {
     "build": "turbo run build",
     "build-storybook": "storybook build",