wayland IME: Discard completed delete request

[dcz-self]

This is a fix. The deletion request would repeat until the next deletion request.

It makes me wonder if Option::take() on every value separately is the right choice here. It goes completely unnoticed when missing. Perhaps there should be a .reset() at the end, resetting all the values to default instead.

• Tested on all platforms changed
• Added an entry to the changelog module if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality