Include hidapi error message on open failrues

[legonigel]

HIDAPI has an error message for open failures, which this appends to the existing unable to open message.

I tested this locally without building just through a simple command line:

>>> import hid
>>> dev = hid.Device(vid=0x0d8c, pid=0x000c)
Traceback (most recent call last):
  File "<python-input-1>", line 1, in <module>
    dev = hid.Device(vid=0x0d8c, pid=0x000c)
  File "/home/nigel/aioc-util/venv/lib/python3.13/site-packages/hid/__init__.py", line 177, in __init__
    raise HIDException('unable to open device')
hid.HIDException: unable to open device
>>> print(hid.hidapi.hid_error(0))
No HID devices with requested VID/PID found in the system.