segfault if checking `roll` argument within Rust code rather than in Python

[MarcoGorelli]

xref #33

if the

        if roll not in (valid_roll_strategies := get_args(RollStrategy)):
            allowed = ", ".join(repr(m) for m in valid_roll_strategies)
            raise ValueError(
                f"`roll` strategy must be one of {{{allowed}}}, got {roll!r}"
            )

check is removed, pytest throws a segfault when running on all tests

[MarcoGorelli]

resolved now, the next polars release will fix this