Get rid of Timidity++

[SilverRainZ]

Timidity++ is not maintained since 2004: https://timidity.sourceforge.net/#news

2 ways:

• Allow custom synthesizer
• Migrate to FluidSynth (still maintained)
• or more: https://www.linuxlinks.com/synthesizers/

[SilverRainZ]

• https://github.com/nwhitehead/pyfluidsynth
• https://github.com/bzamecnik/midi2audio