Version 4.3.5: Bug fixes and enhancements

This update contains enhancements and minor bug fixes and is recommended for all users.

Enhancements

• Add Home Assistant MQTT Auto-Discovery and active/playing State Messages. Thanks to aaronk6 for their considerable work and code -- see this PR.
• Send pvol metadata on mute, thanks to Tucker Kern.
• Ensure the PipeWire backend is initially inactive and that it goes active at the start of a play session and inactive at the end. This is to facilitate external activity-monitoring software. Thanks to Nemo157. Note that in AirPlay 2, play often stops momentarily between tracks, and so there will be momentary changes from active to inactive and back to active again in the PipeWire backend. This may change as the backend improves.
• Update comments in the sndio section of the sample configuration file.

Docker Enhancements

• The AirPlay 2 Docker image now incorporates the PipeWire backend. Thanks to Maxim for the PR.

Bug Fixes

• Update the sndio backend (native to OpenBSD, also used in FreeBSD) to deal with an intermittent bug. Specifically, use an explicit is_running flag to keep track of the playing status of the backend. Thanks to Jan Przybylak, Klemens Nanni and Amanda Stjerna for their help and persistence tracking down this problem. Resolves issue: #1765.
• Fix a bug in the Jack Audio backend. If the system's Jack Audio server was running at anything other than 44,100 frames per second, the delay information being returned by the backend was incorrect. Thanks to lucianoiam.
• Fix an incompatibility with the recently-introduced FFmpeg version 7. Thanks to Deyan Dragov.
• Stop advertising the SFTP and SSH services on Bonjour. Thanks to Jean-Philippe Baril.

Deprecations

• The soundio backend is deprecated and will be removed in a future update. It seems that nobody is using it, and as it stands it is very inflexible.