Type of `Requirement.specs` is incorrect

[wch]

The type of Requirement.specs is declared to be List[str]:

requirements-parser/requirements/requirement.py

Line 90 in 1ce9236

self.specs: List[str] = []

However, the actual type is List[Tuple[str, str]], like [('>', '1.5'), ('<', '1.6')].

The value is assigned here, and the type of the source value is declared as [list[tuple[str, str]]. The # type: ignore isn't needed on that line.