Remove warning when aliases cannot be expanded

[naserca]

• The warning is trying to do the job of mix xref from a place of incomplete information. As the warning itself implies, it may be inaccurate.
• This is why ecto and phoenix and oban and other libs who expand like this don't try to warn in cases like "set a module attribute, use it."
• In fact, the example in the comments here doesn't actually cause a compile-time dep.
• In the case of false positives like this, this warning scares the engineer unnecessarily. We are experiencing this currently :)
• Instead the canonical libraries (ecto, etc) leave it to the compiler and mix xref to let the engineer know if there's a compile-time dep problem.

[coveralls]

Pull Request Test Coverage Report for Build 222163f205c6c02dda2540a463b9d6e52035a5f1-PR-123

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.4%) to 82.796%

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Totals
Change from base Build e84dea09575afff8710bab7ada75e1262ddeb082:	0.4%
Covered Lines:	308
Relevant Lines:	372

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💛 - Coveralls

[mathieuprog]

What do you think of making the warning optional and in the log say someth like: if you do not wish to see this warning due to false positive, do X?

[naserca]

IMO even a flag isn't appropriate since no canonical elixir libraries do this. Since one can't determine during compilation of the file itself if a dependency will be troublesome, other libs leave it to mix xref, the compiler, and the engineers working on a proj to resolve any issues.

But! It's your library, so I'm fine to add a flag if you'd prefer. Let me know!