run-tests: stop writing a `python3` symlink pointing to python2...
run-tests: stop writing a `python3` symlink pointing to python2
Having `python3` actually pointing to `python2` is bad. So we stop doing so.
In addition we need to re-introduce a `python` executable since some of the
script really need to be able to say "current python" in their shbang. For
example, `hghave` is one of such script.
The faulty changes where introduced by c102b704edb5.
Differential Revision:
https://phab.mercurial-scm.org/D10943
