turn off auto-idle by default on Windows

[jwahlstrand]

I think this is the right default for Windows. The lag caused by using Gtk on Windows is very frustrating. See https://github.com/timholy/ProfileView.jl/issues/205

[Vexatos]

Not sure whether this will fix all of the keyboard lag, as the changed line was introduced in #607 in 2022 while the keyboard input issue on Windows has been known since at least 2018. We tried turning off the GTK_AUTO_IDLE variable for a different issue (#610) and it did not resolve the perceived keyboard input lag, so I have my doubts. Any attempt at resolving this long-standing issue is highly appreciated though.