Speed up many commands — remove checks for config management

[dalin-]

Do we or would we ever try to use these commands on a D8/9/10 site that doesn't use Configuration Management? I'm pretty confidently saying "no". So we can remove the checks for Config module, and Config Split (this check was only important because in Drupal 8.0 and 8.1 you needed two different drush commands for sites with/without it).

Removing this might save as much as 30s on:

• pantheon-deploy
• pantheon-multidev-*

[Yuvania]

@dalin- I can do it?

[dalin-]

@Yuvania You're the maintainer, so you do whatever you like ;-)

[Yuvania]

You're the maintainer, so you do whatever you like ;-)

GREAT :D