change default code_theme of CodeInput

Author: agoscinski

src/scwidgets/code/_widget_code_input.py

@@ -20,7 +20,7 @@ def __init__(
         function_parameters: Optional[str] = None,
         docstring: Optional[str] = None,
         function_body: Optional[str] = None,
-        code_theme: str = "north",
+        code_theme: str = "default",
     ):
         if function is not None:
             function_name = (