Make ember-auto-import@2 a dependency

[SergeAstapov]

This is breaking change but would allow us to convert the addon to v2 format in a minor release

[chriskrycho]

💙

[bertdeblock]

I'm unsure if this is correct. AFAIK, it's the consuming app that needs Embroider or ember-auto-import v2 to use a v2 addon. That's what's also mentioned in the v2 addon blueprint:
https://github.com/embroider-build/addon-blueprint/blob/main/files/README.md#compatibility.

[SergeAstapov]

@bertdeblock idea behind this is that v2 addon requires consuming app to either use Embroider or have eai v2, as you said.
Any addon consuming v2 addon or addon with eai v2 also needs to be either v2 adon or have eai v2 (which probably not an issue for this addon).

however, any addon having eai v2 as dependency, also requires the app to have eai v2.
If addon didn’t have it before or used eai v1 - this is breaking change now to require eai v2.

idea of this PR is to make a breaking change now.

and once someone has a bandwidth, now we can convert to v2 addon fromat without breaking change.

[bertdeblock]

@ember/test-helpers doesn't use any v2 addons and doesn't import any normal npm packages as far as I can tell, so technically it doesn't need ember-auto-import in dependencies in the first place I think?
I guess I don't understand why it's important to be able to do the v2 conversion in a minor release.

[SergeAstapov]

I guess I don't understand why it's important to be able to do the v2 conversion in a minor release.

Only to avoid another major release, no other real reason.