Remove the option to pass None in warns()

Author: olgarithms

src/_pytest/recwarn.py

@@ -84,7 +84,7 @@ def deprecated_call(
 
 @overload
 def warns(
-    expected_warning: Optional[Union[Type[Warning], Tuple[Type[Warning], ...]]] = ...,
+    expected_warning: Union[Type[Warning], Tuple[Type[Warning], ...]] = ...,
     *,
     match: Optional[Union[str, Pattern[str]]] = ...,
 ) -> "WarningsChecker":
@@ -93,7 +93,7 @@ def warns(
 
 @overload
 def warns(
-    expected_warning: Optional[Union[Type[Warning], Tuple[Type[Warning], ...]]],
+    expected_warning: Union[Type[Warning], Tuple[Type[Warning], ...]],
     func: Callable[..., T],
     *args: Any,
     **kwargs: Any,
@@ -102,9 +102,7 @@ def warns(
 
 
 def warns(
-    expected_warning: Optional[
-        Union[Type[Warning], Tuple[Type[Warning], ...]]
-    ] = Warning,
+    expected_warning: Union[Type[Warning], Tuple[Type[Warning], ...]] = Warning,
     *args: Any,
     match: Optional[Union[str, Pattern[str]]] = None,
     **kwargs: Any,