Remove useless check since args are always array (can be empty)

Replicates graphql/graphql-js@bb07ecc

Author: Cito

src/graphql/execution/values.py

@@ -119,10 +119,10 @@ def get_argument_values(
     of argument AST nodes.
     """
     coerced_values: Dict[str, Any] = {}
-    arg_defs = type_def.args
     arg_nodes = node.arguments
-    if not arg_defs or arg_nodes is None:
+    if arg_nodes is None:
         return coerced_values
+    arg_defs = type_def.args
     arg_node_map = {arg.name.value: arg for arg in arg_nodes}
     for name, arg_def in arg_defs.items():
         arg_type = arg_def.type

src/graphql/type/schema.py

@@ -281,10 +281,8 @@ def type_map_reducer(
 
         if is_object_type(type_) or is_interface_type(type_):
             for field in cast(GraphQLInterfaceType, type_).fields.values():
-                args = field.args
-                if args:
-                    types = [arg.type for arg in args.values()]
-                    map_ = reduce(self.type_map_reducer, types, map_)
+                types = [arg.type for arg in field.args.values()]
+                map_ = reduce(self.type_map_reducer, types, map_)
                 map_ = self.type_map_reducer(map_, field.type)
 
         if is_input_object_type(type_):