Replace creation of set on every `span.status` call with frozen set

[ericapisani]

Within the status setter method on the StreamedSpan class, we create a new set containing the options from the SpanStatus enum to check if the value provided is valid.

This is a small performance hit that can easily be removed by using either a tuple or a frozenset, especially given this function is in the hot path of a lot of integrations

[linear-code]

PY-2403