Hard Zod dependency

[endel]

Hi there,

I noticed you're working on version 2.0, it would be nice to make the "zod" dependency actually optional, right now we'd get a runtime error if using the module without "zod" as dependency, see:

import { createEndpoint, createRouter } from "better-call";

const endpoint = createEndpoint("/item", { method: "GET" }, async (ctx) => {
   return "ok";
})

const router = createRouter({ endpoint })

Bun.serve({
    fetch: router.handler
})

This gives this error:

❯ bun run index.js
error: Cannot find package 'zod' from 'node_modules/better-call/dist/openapi.mjs'

Cheers