Enum.max_by/3 and Enum.min_by/3 dialyzer fixes

[davydog187]

I was getting dialyzer errors when calling min_by and max_by arity 3.

# Code
Enum.min_by(matches, & &1.utc_start_time, DateTime)

# Error
lib/trailblazer_web/controllers/api/v1/match_controller.ex:56:call
The function call will not succeed.

Enum.max_by(_matches :: [any(), ...], (_ -> any()), DateTime)

breaks the contract
(t(), (element() -> any()), (() -> :empty_result)) :: element() | :empty_result
when empty_result: any()

[josevalim]

💚 💙 💜 💛 ❤️

[michallepicki]

@davydog187 I am curious, did you have this problem with 1.11.0-rc.0? I thought I fixed it in #10050 already. I cannot reproduce with 1.11.0-rc.0 and looking at your PR it doesn't really change the specs, just merges existing specs into one (?)

[davydog187]

@michallepicki I didn't. Let me fire it up and see if I can reproduce