Update the C3 behavior for Cloudflare Workers template

[yusukebe]

Currently, if we create a new Cloudflare Workers project with C3, C3 will add the following code to index.ts:

type Bindings = {
  [key in keyof CloudflareBindings]: CloudflareBindings[key]
}

This snippet does convert interface to type because new Hono() does not accept interface before.

But, since v4.5.0, we can pass an interface to it! We can remove that snippet and pass the CloudflareBindings directly.