.env file don't load in config

[SimoMay]

Environment

Node v16.15.0
npm 8.5.5
nitropack ^0.4.4

Reproduction

Reproducing this is simple, FYI, I'm using Nitro without Nuxt.
If you follow the documentation you would end up with something like this in nitro.config.ts:

import { defineNitroConfig } from 'nitropack'

export default defineNitroConfig({

  runtimeConfig: {
    supabase: {
      api_url: '',
      api_anon_key: ''
    }
  }
  // extends: [
  //   'config.dev.ts'
  // ]
})

And .envfile:

NITRO_SUPABASE_API_URL='xx'
NITRO_SUPABASE_API_ANON_KEY='yy'

Trying to read the values in a route with:

export default () => {
  const config = useRuntimeConfig()
  return config
}

you get empty values (the defaults).

{
  "app": {
    "baseURL": "/"
  },
  "nitro": {
    "routes": {}
  },
  "supabase": {
    "api_url": "",
    "api_anon_key": ""
  }
}

While the expected behavior is to find the values from the .env file:

{
  "app": {
    "baseURL": "/"
  },
  "nitro": {
    "routes": {}
  },
  "supabase": {
    "api_url": "xx",
    "api_anon_key": "yy"
  }
}

Describe the bug

I figured from reading the code, that Nitro suppose to get values from .env using unjs/c12 & dotenv while looping for values in the file that start with NITRO_ prefix, but it doesn't work (at least on my local)

I found a solution that works for me, which is importing dotenv at the start of nitro.config.ts, which solves this issue.

If this is the standard way to do so, then I assume an example of it in the documentation would be helpful (it took me a long time to figure it out myself)

If this is not the standard way, which is what I believe to be so, then importing dotenv in the beginning of the [src/options.ts](https://github.com/unjs/nitro/blob/b153cea1f2e0805088bdc512f490539cccec69c4/src/options.ts) could solve the issue.

Additional context

What solved it for me is adding import 'dotenv/config' at the top:

import 'dotenv/config'
import { defineNitroConfig } from 'nitropack'

export default defineNitroConfig({

  runtimeConfig: {
    supabase: {
      api_url: '',
      api_anon_key: ''
    }
  }
...

Logs

No response

[SimoMay]

Discussed in #238