96a1c82a

By: Greg Pfeil <greg@technomadic.org>

Don’t package firmware in simulator builds

Discovered this when `build.py -o simulator` failed on macOS despite
successfully building the simulator.

The failure was due to there being no `python` symlink (fixed in the previous
commit). But having it succeed produced an invalid firmware alongside the
simulator. The simulator build now skips the steps to produce the firmware.