linux: Keep pipewire devices between connections

This is an alternative to implementing something to set it as default. We could just add a note in the audio settings and that'd be that. And it solves some issues people reported with discord acting up when audio devices are frequently removed and readded (which might be annoying if that happens because of a short connection dropout).

Tho I'm not sure how good of an idea it is. It would likely consume no resources if we just don't send samples but idk how changing the sample rate would be handled etc.