Upgrade MicroPython to 2.1.0 and 1.1.0. (#1003)

https://github.com/microbit-foundation/micropython-microbit-v2/releases/tag/v2.1.0
https://github.com/bbcmicrobit/micropython/releases/tag/v1.1.0

Stubs changes from microbit-foundation/micropython-microbit-stubs#72

Co-authored-by: Robert Knight <[email protected]>

Author: microbit-matt-hillsdon