[BUG]: Column name not being returned as snake_case

### What version of `drizzle-orm` are you using?

0.34.1

### What version of `drizzle-kit` are you using?

0.25.0

### Describe the Bug

When using `casing: 'snake_case'` in the config and defining a column like so `firstName: t.text().notNull()`

And then when accessing the column name via `users.firstName.name` we get `firstName` instead of `first_name`

Same happens if we get the columns via `getTableConfig(users).columns` and `getTableColumns(users)`

### Expected behavior

_No response_

### Environment & setup

_No response_