mark: allow any Sequence[str] for parametrize(argnames), not just list/tuple

The main motivation for this change is to simplify the type shown in
code editors -- `Sequence[str]` is easier to follow than
`Union[list[str], tuple[str, ...]]`.

It also permits using other types if desired. It might lead to problems
if someone uses some oddball sequence type, but hopefully they won't do
that.

src/_pytest/python.py

@@ -1207,7 +1207,7 @@ class Metafunc:
 
     def parametrize(
         self,
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union[ParameterSet, Sequence[object], object]],
         indirect: Union[bool, Sequence[str]] = False,
         ids: Optional[