Change Mapping to dict in resolution Result type annotations

[webknjaz]

typing.Mapping is a broad concept. The actual code just assigns dicts so Result should just use that.

I've been adding annotations to the calling side (ansible-galaxy) that uses resolvelib and hit this as I was trying to show that a function that returns Resolver(...).resolve(...).mapping produces a dict.

[notatallshaw]

Is it not expected that anyone is sub-classing AbstractResolver to implement their own Resolver? I don't think pip is, but if anyone else is this technically changes the API for resolvelib.

Could this be done at the `Resolver(...).resolve(...) level instead? Or does that break some type theory invariant?

I'm not against this, just thinking about where things could go wrong.

[webknjaz]

@notatallshaw AFAIK, only the AbstractProvider needs to be inherited. Also, if somebody is substituting entire main components of a library they are effectively not using the library in the end.

This cannot be done on the Resolver(...).resolve(...) because it returns a Result object which has a broadly typed attribute. Currently, I'm fighting this with type narrowing: https://github.com/ansible/ansible/pull/85545/files#r2394287530. But I think the types should be fixed here. After all, other components in the repo use dict. So this seems inconsistent.

[notatallshaw]

Great, let's do this.