Fix blurry cursor on Wayland at a scale other than 100%

[senonide]

Closes #13258

Release Notes:

• Fixed blurry mouse cursor on wayland when the screen scale is other than 100%

Before:

After:

[mikayla-maki]

Thanks!

[CharlesChen0823]

// FIXME: Determine the scaling factor dynamically by the compositor

this should fix, because when scaling factor is 100%, the display cursor is too big.

[notpeter]

@senonide Don't know if you saw this:

• Mouse Pointer wrong size (Linux) #17771

Likely caused by this:

zed/crates/gpui/src/platform/linux/wayland/client.rs

Lines 479 to 480 in 0d9af4d

	// FIXME: Determine the scaling factor dynamically by the compositor
	let mut cursor = Cursor::new(&conn, &globals, 24, 2);

[apricotbucket28]

This code in here is wrong, the cursor's scale must be determined by the scale of the current wl_surface. Here's some code where this is already being done. Basically:

1. Use PreferredBufferScale event if available (surface.version() >= wl_surface::EVT_PREFERRED_BUFFER_SCALE_SINCE)
2. Else, use the scale in wl_surface::Event::Enter/Leave.

The PreferredScale event doesn't work for this since it sends a fractional scale.

Maybe there should be a cursor theme cache like SCTK does, and the current window's scale should passed when calling cursor.set_icon(): https://github.com/Smithay/client-toolkit/blob/c583de8dd5651f8168c6513cd282137c42aae049/src/seat/pointer/mod.rs#L612-L635