Left SHIFT causes 2 SDL_KEYDOWN events on MacOS on 2.26.0+ (works on 2.24.2)

[jsm174]

We are currently working on a port of Visual Pinball for MacOS, Linux, Android, and iOS.

After upgrading SDL2 to 2.26.0+ on MacOS, we receive two SDL_KEYDOWN events when the user presses the LEFT shift key.

https://user-images.githubusercontent.com/1197137/208102078-5b303e84-bdc4-468e-84ec-f6376233c489.mp4

(This eventually causes the left flipper to stick in an up position when multiple keys are pressed.)

I downgraded to SDL2 2.24.2 and it works as expected.

FWIW, iOS does not have this behavior in 2.26.0+. Android seems to getting repeating keys, but I need to debug this first.