add annotation_parens

src/black/linegen.py

@@ -200,9 +200,6 @@ def visit_dictsetmaker(self, node: Node) -> Iterator[Line]:
 
     def visit_funcdef(self, node: Node) -> Iterator[Line]:
         """Visit function definition."""
-        if Preview.annotation_parens not in self.mode:
-            yield from self.visit_stmt(node, keywords={"def"}, parens=set())
-        else:
         yield from self.line()
 
         # Remove redundant brackets around return type annotation.

src/black/mode.py

@@ -149,7 +149,6 @@ def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> b
 class Preview(Enum):
     """Individual preview style features."""
 
-    annotation_parens = auto()
     prefer_splitting_right_hand_side_of_assignments = auto()
     # NOTE: string_processing requires wrap_long_dict_values_in_parens
     # for https://github.com/psf/black/issues/3117 to be fixed.