Auto import inserts at incorrect position if it's after multibyte/wide characters

[s-cerevisiae]

Make sure you have done the following

• I have updated to the latest version of blink.cmp
• I have read the README

Bug Description

When auto import is inserted after lines that contain multi-byte (or wide?) characters, it inserts at a wrong position and cuts up bytes in previous lines.

Reproduction:
https://github.com/s-cerevisiae/blink-cmp-issues/blob/master/src/bin/auto_import.rs
(doesn't include the result after auto import because it kills rust-analyzer immediately)

Relevant configuration

{}

neovim version

v0.10.2

blink.cmp version: branch, tag, or commit

main (56f7cb6)