Fixed _dumb.py

pickup void should be pickup_data from dumb.h
Added audioop check for pypy3

pypy3 doesn't have audioop yet so disable some functionality if it is not
found.
Remove sincosl and modfl

sincosl and modfl don't work in pypy3 ctypes, and the are not used by musio, so
remove them for now.
Skip modules that fail to import.
Add a workaround for pypy3

pypy3's print function doesn't have flush yet so use sys.stdout.flush()
instead.