fix: SAWarning: requiring to specify

[edupo]

Fixing the issue with #110.

I believe this may be a bug with SqlAlchemy when using a different base than the one defined by SQA itself... They get the attribute inherit_cache like:

inherit_cache = cls.__dict__.get("inherit_cache", None)

This returns None while just doing:

cls.inherit_cache

Does return the True they are looking for.

The workaround I propose to sqlathanor is just to override the class variable in some schema classes to avoid those warnings.