Changing cursor properties while window is being resized crashes in browser

Description

Reproducer: https://github.com/benjamin-sieffert/curs-reprod

Calling cursor-related functions, e.g. set_cursor_visible while the browser window containing winit+wgpu application is being resized, leads to a panic. This happens even when the state of the cursor would not even change (e.g. always calling set_cursor_visible(true)).

The error is:
winit-0.30.8/src/platform_impl/web/event_loop/runner.rs:599:30 (already borrowed: BorrowMutError)

I understand that due to rendering and event delivery interfering with each other, it may not be possible to make this "work."
It would be nice if it did not panic. Some cursor functions also return ExternalError already, this could be used to signal failure instead of a panic.

Cheers

Tested browsers

Chrome, Firefox

Tested devices

Linux PC
Windows PC

Winit version

winit: 0.30.8
wgpu: 24.0.1

Start with the web event-loop implementation at winit-0.30.8/src/platform_impl/web/event_loop/runner.rs:599 and reproduce the panic using the linked curs-reprod project while resizing the browser window. Trace the cursor-related calls and the existing ExternalError behavior. Done means repeated cursor changes during resizing no longer panic, with failure reported through the existing API where applicable.