Since the bin/uf2conv/uf2conf.py script uses python3, use python3 as the command instead of python.
On my ubuntu 24.04 machine, I don't have a python command in my path by default
* Enable the new UI on the BLE and USB Companion roles.
* Fix compilation issues with the repeater and room server roles.
* Remove ESP32-related alternate pinout cruft from the NRF build tree.
* build.sh: add build-matching-firmwares command to allow e.g. building
all roles for a given variant by passing the variant name.
