`ToSchema` derive disrupts `#[allow(non_snake_case)]`

[James-Mart]

Not high priority, but some of our services will have extra warnings:

[swatanabe]

I can't reproduce this.

Both of the following compile without warnings:

#[derive(ToSchema)]
#[fracpack(fracpack_mod = "fracpack")]
#[allow(non_snake_case)]
pub struct Foo {
    pub Bar: i8,
}

#[allow(non_snake_case)]
mod service {
    #[derive(ToSchema)]
    #[fracpack(fracpack_mod = "fracpack")]
    pub struct Foo {
        pub Bar: i8,
    }
}