Atmos audio is not always selected / prioitized

[Dreamer269]

Describe the bug
Some services have Atmos audio with a lower bitrate than the normal audio tracks. For example, normal E-AC-3 640 kb/s vs. atmos E-AC-3 448 kb/s.

To Reproduce
Steps to reproduce the behavior:

1. Download a title with Atmos audio from the service.

Expected behavior
Since atmos is considered superior, it should be selected instead of the 640 kb/s audio track.

Additional context
This seems to be caused by the following code in sort_audio (tracks.py):

        self.audio.sort(
            key=lambda x: float(x.bitrate or 0.0),
            reverse=True
        )```