Fix macro pollution in SystemParam derive (#19155)

# Objective

Fixes #19130 

## Solution

Fully quality `Result::Ok` so as to not accidentally invoke the anyhow
function of the same name

## Testing

Tested on this minimal repro with and without change.

main.rs
```rs
use anyhow::Ok;
use bevy::ecs::system::SystemParam;

#[derive(SystemParam)]
pub struct SomeParams;

fn main() {
}
```
Cargo.toml
```toml
[package]
name = "bevy-playground"
version = "0.1.0"
edition = "2024"

[dependencies]
anyhow = "1.0.98"
bevy = { path = "../bevy" }
```

crates/bevy_ecs/macros/src/lib.rs

@@ -455,7 +455,7 @@ pub fn derive_system_param(input: TokenStream) -> TokenStream {
                         <#field_types as #path::system::SystemParam>::validate_param(#field_locals, _system_meta, _world)
                             .map_err(|err| #path::system::SystemParamValidationError::new::<Self>(err.skipped, #field_messages, #field_names))?;
                     )*
-                    Ok(())
+                    Result::Ok(())
                 }
 
                 #[inline]