SPI Bus interference from SDCard

In testing a recent PR I noticed that using the RFM9x Radio FeatherWing on a PyGamer (7.3.0-beta.2) when I have an SDCard plugged in the radio doesn't behave correctly. It will cause the same message to get received over and over again rapidly, as well as messages after the first one not being received by the other side.

Removing the SDCard and then re-running the same examples on the same devices then works successfully and behaves as expected when the SDCard is not plugged in.

My best guess is that something internally within the core is perhaps initializing or starting communications with the SDCard on the SPI bus and that is causing interference when the RFM9x radio tries to communicate on the same SPI bus.

Start by reproducing the issue on a PyGamer with the RFM9x Radio FeatherWing and an SDCard, running the same examples with and without the card under CircuitPython 7.3.0-beta.2. Trace the shared SPI-bus communication and verify completion by confirming that messages are received once and subsequent messages reach the other device while the SDCard remains plugged in.

Written by the indexing model from the issue text.