Allow ember-cli-babel >= v8 for apps and addons

[bertdeblock]

No description provided.

[ef4]

Since the point of this check is to make sure the app is using babel 7, when we encounter ember-cli-babel 8 I think we need to actually check the app's version of @babel/core itself.

if (app has ember-cli-babel 7) {
  we're definitely using @babel/core 7
} else if (app has ember-cli-babel > 7) {
  we need to check what version of @babel/core is in the app
}

[ef4]

Thanks!

[ef4]

Released in @embroider/compat 2.2.1.