Switch back to stock CircuitPython build

[ulfmagnetics]

We're using a custom build of CircuitPython to fix a compatibility issue with the ESP32 SPI library. Since adafruit/Adafruit_CircuitPython_ESP32SPI#218 has been merged, we should be able to switch back to the standard build once a new version has been released.

[ulfmagnetics]

Now that I've migrated to the MatrixPortal S3 this no longer applies. The ESP32-S3 has onboard WiFi so there is no need to use the ESP32-SPI library.