This hint is an integer > 0, that represents the size of the device's buffer in sample frames (stereo
audio data in 16-bit format is 4 bytes per sample frame, for example).
SDL3 generally decides this value on behalf of the app, but if for some reason the app needs to dictate
this (because they want either lower latency or higher throughput AND ARE WILLING TO DEAL WITH what that
might require of the app), they can specify it.
SDL will try to accommodate this value, but there is no promise you'll get the buffer size requested.
Many platforms won't honor this request at all, or might adjust it.
This hint should be set before an audio device is opened.