devel/py-types-typed-ast: Add py-types-typed-ast 1.5.4

This is a PEP 561 type stub package for the typed-ast package. It can be used by
type-checking tools like mypy, PyCharm, pytype etc. to check code that uses
typed-ast.

WWW: https://github.com/python/typeshed/tree/master/stubs/typed-ast