Allow ctrl-c of adafruit_bus_device.spi_device lock hang

[dhalbert]

• Fixes native adafruit_bus_device.spi_device.SPIDevice will hang and disconnect if device is locked #9054

The __enter__() for the native SPIDevice context manager would spin waiting for the lock. It did not check for ctrl-c or run background tasks.

This is an old bug: it is present in 8.x.x and probably before, so doesn't need to be included in 9.0.0 final.

Tested with the test program in #9054. Now it does:

>>> import spilock
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "spilock.py", line 8, in <module>
        [typed ctrl-C here]
KeyboardInterrupt: 
>>> 

[tannewt]

Thank you!