termux_step_rust makes more sense to have in
termux_step_pre_configure, the carbo build step in termux_step_make
and the install step in termux_step_make_install.
In issue https://github.com/termux/termux-packages/issues/6160 I have found
that community repo "its-pointless.github.io" specifies us as maintainer
for its packages. This is NOT TRUE and potentially misleads people using
these packages.
Now TERMUX_PKG_MAINTAINER will contain a default value which is neutral
and not specify maintainer. So all packages now have to override it to
the correct value.
[skip ci]
%ci:no-build
