* Properly register submodules of ulab
This is related to
* https://github.com/adafruit/circuitpython/issues/6066
in which, after the merge of 1.18 into CircuitPython, we lost the ability
to import submodules of built-in modules.
While reconstructing the changes we had made locally to enable this,
I discovered that there was an easier way: simply register the dotted
module names via MP_REGISTER_MODULE.
* Fix finding processor count when no `python` executable is installed
debian likes to install only `python3`, and not `python` (which was,
for many decades, python2).
This was previously done for `build.sh` but not for `build-cp.sh`.
* Only use this submodule feature in CircuitPython
.. as it does not work properly in MicroPython.
Also, modules to be const. This saves a small amount of RAM
* Fix -Werror=undef diagnostic
Most CircuitPython ports build with -Werror=undef, so that use of an
undefined preprocessor flag is an error. Also, CircuitPython's micropython
version is old enough that MICROPY_VERSION is not (ever) defined.
Defensively check for this macro being defined, and use the older style
of MP_REGISTER_MODULE when it is not.
* Fix -Werror=discarded-qualifiers diagnostics
Most CircuitPython ports build with -Werror=discarded-qualifiers.
This detected a problem where string constants were passed to functions
with non-constant parameter types.
* bump version number
* Use MicroPython-compatible registration of submodules
* straggler
* Remove spurious casts
these were build errors for micropython
* Run tests for both nanbox and regular variant during CI
