Don't auto import items when one is already in scope

I'm not sure if this was a client error (neovim) or a r-a error, but there are times where I import another item.

use ratatui::layout::Layout;

fn f () {
  let layout = Lay [completions show, press enter]
}

use ratatui::layout::Layout;
use std::alloc::Layout; // ???

fn f () {
  let layout = Lay [press enter]
}

I don't know if I was just too fast and the completion for alloc's Layout got completed faster than the one in scope maybe? I tried again and I can't replicate it.
(I'm 100% sure I didn't mistakinly press the arrow keys to select another one)

Start by reproducing the completion behavior described in the Rust and Neovim snippets, checking whether an item already in scope can trigger an incorrect auto-import. Compare the client interaction and completion choice, then verify that accepting the in-scope item no longer adds an unrelated import.