audio/fluidsynth: Update to 2.4.4

Support SDL 3.x and group SDL options into a RADIO options group.
Note: This is temporary. SDL 2.x support has been deprecated in this
release and will be removed in fluidsynth 2.5.x.

Add INSTPATCH option. Boy howdy! This has not been re-evaluated in quite
a while.

Remove unnecessary pthread hack from Makefile.

Remove overly paranoid CMake arguments added in c4d5a141aa97. Upstream
ships a rather compentent configure process and there is no need to
supply unnecessary arguments.

https://github.com/FluidSynth/fluidsynth/releases/tag/v2.4.4