Relax bind() argument type to Mapping

[mthuurne]

Currently Binder.bind() takes a dict argument:

dataclass-binder/src/dataclass_binder/_impl.py

Line 346 in 8e74701

def bind(cls, data: dict[str, Any]) -> T:

However, as we don't modify the argument, Mapping would suffice. This would make the binder able to parse data structures from other sources than tomllib.