extensions: avoid enabling evolve for unrelated repositories (issue6057) The support for the `experimental.evolve` config have been there forever. So we can stop using the global variable. This help avoiding evolve to enable itself of repository that did not explicitly activated it. For example, this is useful for hgwebdir. Before this change, evolution feature had to be explicitly disabled or enabled in every single repository.

#require test-repo pyflakes

Copied from Mercurial core (60ee2593a270)

  $ cd "`dirname "$TESTDIR"`"

run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)

  $ hg locate -I 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
  > | xargs pyflakes 2>/dev/null