main/nodejs: use python3 in makedepends
So that python2 could be moved to community, see #11577 (closed)
Following advice in https://github.com/nodejs/help/issues/2363#issuecomment-568077773
We are currently working on getting Alpine Linux 3.21 out. This means that merge requests that are not aimed to help with that (only affecting testing, new aports) have a lower priority at the moment. Please be patient, they will be eventually picked up.
So that python2 could be moved to community, see #11577 (closed)
Following advice in https://github.com/nodejs/help/issues/2363#issuecomment-568077773