Closes #35316

Bug in https://github.com/zed-industries/zed/pull/34514

Turns out you are not supposed to call `update_key` for modifiers on
`KeyPress`/`KeyRelease`, as modifiers are already updated in
`XkbStateNotify` events. Not sure why this only causes issues on a few
systems and works on others.

Tested on Ubuntu 24.04.2 LTS (initial bug) and Kubuntu 25.04 (worked
fine before too).

Release Notes:

- Fixed an issue where caps lock stopped working consistently on some
Linux X11 systems.