Add a setting to not pause on audio focus loss

Checklist

• I have used the search function for OPEN issues to see if someone else has already submitted the same feature request.
• I have also used the search function for CLOSED issues to see if the feature was already implemented and is just waiting to be released, or if the feature was rejected.
• I will describe the problem with as much detail as possible.
• This request contains only one single feature, not a list of multiple (related) features.

App version

3.12.0

Feature or improvement you want

With the new playback service, the option to duck volume for received notifications has been removed. Is it possible to add it back or is it a hard limitation?

Relevant PR: https://github.com/AntennaPod/AntennaPod/pull/8433 Relevant forum post: https://forum.antennapod.org/t/behavior-on-incoming-notifications/8663 Also somewhat related: https://github.com/AntennaPod/AntennaPod/issues/8333

Why should this be added?

Pausing playback for notifications is really annoying.

Screenshots / Drawings / Technical details

No response