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.

Author: bluetech

changelog/10218.improvement.rst

@@ -0,0 +1,5 @@
+``@pytest.mark.parametrize()`` (and similar functions) now accepts any ``Sequence[str]`` for the argument names,
+instead of just ``list[str]`` and ``tuple[str, ...]``.
+
+(Note that ``str``, which is itself a ``Sequence[str]``, is still treated as a
+comma-delimited name list, as before).

src/_pytest/mark/structures.py

@@ -126,12 +126,12 @@ def extract_from(
 
     @staticmethod
     def _parse_parametrize_args(
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union["ParameterSet", Sequence[object], object]],
         *args,
         **kwargs,
-    ) -> Tuple[Union[List[str], Tuple[str, ...]], bool]:
-        if not isinstance(argnames, (tuple, list)):
+    ) -> Tuple[Sequence[str], bool]:
+        if isinstance(argnames, str):
             argnames = [x.strip() for x in argnames.split(",") if x.strip()]
             force_tuple = len(argnames) == 1
         else:
@@ -150,12 +150,12 @@ def _parse_parametrize_parameters(
     @classmethod
     def _for_parametrize(
         cls,
-        argnames: Union[str, List[str], Tuple[str, ...]],
+        argnames: Union[str, Sequence[str]],
         argvalues: Iterable[Union["ParameterSet", Sequence[object], object]],
         func,
         config: Config,
         nodeid: str,
-    ) -> Tuple[Union[List[str], Tuple[str, ...]], List["ParameterSet"]]:
+    ) -> Tuple[Sequence[str], List["ParameterSet"]]:
         argnames, force_tuple = cls._parse_parametrize_args(argnames, argvalues)
         parameters = cls._parse_parametrize_parameters(argvalues, force_tuple)
         del argvalues
@@ -434,7 +434,7 @@ def __call__(
     class _ParametrizeMarkDecorator(MarkDecorator):
         def __call__(  # type: ignore[override]
             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]] = ...,

src/_pytest/python.py

@@ -1207,7 +1207,7 @@ def __init__(
 
     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[