Don't set the raw mouse motion input mode on macOS

[moomba42]

Currently if you try to use the setInputModeCursor function on macOS, then GLFW will produce the following error.PlatformError: "Raw mouse motion is not supported on this system". This happens for every possible value parameter.
By checking if the platform is macOS, we can avoid this error.

Tested on Macbook Pro M1 with macOS Sonoma 14.5.

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[castholm]

I don't know the full context behind the original change, but I think it's a bit dubious that setInputModeCursor enables/disables the raw mouse motion mode in the first place. If the original GLFW doesn't, then why should the binding?

@xdBronch, it looks like you made the original change in 8e091ce (hexops/mach#795). Do you remember why the change was made originally, and do you think it would make sense to revert it? I figure that users who want both could call e.g.
window.setInputModeCursor(.disabled) followed by window.setInputModeRawMouseMotion(true) just like they would with the original C API.

[xdBronch]

the original discussion was on discord here https://discord.com/channels/996677443681267802/999727330660462704/1114485031797264425
but rereading it im struggling to understand what exactly my motivation was or why it was like this. just making people call both functions sounds fairly reasonable to me but i havent used glfw in quite a while so i couldnt tell you whats the best API