SDFat is included with Arduino Core for RP2040/2350 (Earle Core) - v4.4.2 of core won't build without extra defines

[tyeth]

Adding the defines for FAT12 and USE_BLOCK_DEVICE_INTERFACE allow the build to finish locally, using platformIO, but CI still baulks.
We probably need to stop using the adafruit fork of SDFat for Pico, or include the necessary config before we can update from v4.4.1 to v4.4.2 of Earle Core:
earlephilhower/arduino-pico#2764

[brentru]

Resolved by #706

Closing!