Behavior Change when clientPrefix is empty

[DanSnow]

Issue Description

The behavior of the clientPrefix parameter in the @t3-oss/env-core library has changed, causing unexpected errors.

Example

import { createEnv } from '@t3-oss/env-core'
import { z } from 'zod'

const env = createEnv({
  isServer: false,
  clientPrefix: '',
  client: {
    FOO: z.string(),
  },
  runtimeEnvStrict: {
    FOO: 'FOO',
  },
})

console.log(env.FOO) // Throws error after upgrading to v0.9

In version 0.8, the provided code was functioning correctly. However, after upgrading to version 0.9, executing the same code results in the following error:

Attempted to access a server-side environment variable on the client

[juliusmarminge]

This is intended. If you want a client var without prefix use shared variables

[julius-retzer]

I'm running into same issue and using shared doesn't work. I see that there is this code in source

   const isServerAccess = (prop)=>{
        if (!opts.clientPrefix)
            return true;
        return !prop.startsWith(opts.clientPrefix) && !(prop in shared.shape);
    }

So it means that if we have clientPrefix: '' it will never be accessible on client? I'm always getting the Attempted to access a server-side environment variable on the client if I put the variables in shared, isServerAccess always returns true, even on client