Use openapi in project root with Nuxt 4 layout

[IlyaSemenov]

With Nuxt 4 layout enabled with future: { compatibilityVersion: 4 } in nuxt.config.ts, which features separate app/ and server/ root directories, I would expect nuxt-open-fetch to pull openapi.yaml from openapi/pets/openapi.yaml, as it provides both client-side and Nitro server integration.

Currently, nuxt-open-fetch looks for app/openapi/pets/openapi.yaml, which is counterintuitive.