[bug#72142] [PATCH v1] Fix formatting, boost not needed in python-rtmidi

[jgart]

> + (inputs (list glibc python-cffi jack-2 rtmidi))

Hi, since this is a Python library, do we want to make the Python inputs 
propagated?

Were you able to test in a shell that the following works fine when run from a 
script or repl?

If not, can you test that and report back on the results. I'll give it a try 
after.

Or, how have you gone about testing that this package works in a Guix 
environment with all the system audio requirements?


```python
import time
import rtmidi

midiout = rtmidi.MidiOut()
available_ports = midiout.get_ports()

if available_ports:
    midiout.open_port(0)
else:
    midiout.open_virtual_port("My virtual output")

with midiout:
    note_on = [0x90, 60, 112] # channel 1, middle C, velocity 112
    note_off = [0x80, 60, 0]
    midiout.send_message(note_on)
    time.sleep(0.5)
    midiout.send_message(note_off)
    time.sleep(0.1)

del midiout
```

all best,

jgart