This is a no-op for coverage and minimal.
The standard and dev variants have been merged and enable the same feature
set as a typical bare-metal board. And remove the CI for the dev build.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Invoking "make" will still build the standard "micropython" executable, but
other variants are now build using, eg, "make VARIANT=minimal". This
follows how bare-metal ports specify a particular board, and allows running
any make target (eg clean, test) with any variant.
Convenience targets (eg "make coverage") are provided to retain the old
behaviour, at least for now.
See issue #3043.
