main/postmarketos-ui-phosh: add !pipewire-pulse

Prevent apk from pulling in pipewire-pulse instead of pulseaudio, as this leads to various audio issues with Phosh in postmarketOS (volume buttons not working, no sound in various applications).

Pipewire will be a great replacement for pulseaudio, but let's rather enable it intentionally for Phosh once we fixed everything that's currently breaking with it. Without this patch it may get installed when installing or upgrading other packages (not entirely sure how it gets triggered yet, but I have seen it myself multiple times and we've gotten reports about it).

Also bump min pmbootstrap version to the one that supports conflicting depends (starting with !, as in !pipewire-pulse).

Fix #1386 (closed)