run_api_command leaks file descriptors

When using the C library calls, run_api_command appears to leak file descriptors. Multiple calls to run_api_command in the same process builds up UNIX-STREAM file descriptors (two per call, presumably the in and out descriptors for communicating with the Termux:API plugin).

The created sockets should be closed before returning.

Code to reproduce (via. Python):

import ctypes
import sys
from os import getpid
from signal import pause

run_api_command = ctypes.CDLL("libtermux-api.so").run_api_command
run_api_command.argtypes = [ ctypes.c_int, ctypes.POINTER(ctypes.c_char_p) ]
run_api_command.restype = ctypes.c_int

args = f"{sys.argv[0]} Usb -a list"
argb = args.encode('utf8').split(b' ')
argv = (ctypes.c_char_p * len(argb))(*argb)

run_api_command(len(argv), argv)
run_api_command(len(argv), argv)
run_api_command(len(argv), argv)

print(f"Process ID: {getpid()}")
pause()

Running lsof -p [pid] on the resulting pid will reveal the leaked file descriptors.

Start at the run_api_command entry point in the C library and reproduce the problem with the provided Python ctypes script; inspect the UNIX-STREAM descriptors with lsof. Trace the input and output socket lifecycle and verify that repeated calls no longer leave descriptors open.