Add errno.EROFS and errno.ENOSPC

[dhalbert]

Motivated by https://forums.adafruit.com/viewtopic.php?t=214213. Fixes #9733

errno.EROFS and errno.NOSPC didn't exist, but they get nicer error messages already in mp_common_errno_to_str(). Add them. A user wanted to check for errno.EROFS and was surprised it was not available. errno.EROFS is common, given that CIRCUITPY is read-only when connected to USB.

These have not been added to the smallest builds, for space reasons.

[jepler]

thanks, makes sense.