wayland: Fix input_handler out of range access (#10724)

The wayland implementation takes an input handler from the state, but
only puts it back if the event was an IME key. I flipped the logic to
ensure it's always put back.

This should fix both:
- #10344
- #10652

Release Notes:

- Fixed input_handler out of range access
([#10344](https://github.com/zed-industries/zed/issues/10344),
[#10652](https://github.com/zed-industries/zed/issues/10652)).