Fix default value of target_versions parameter in black config

Author: Aksem

extensions/fine_python_black/fine_python_black/action.py

@@ -50,7 +50,7 @@ class BlackFormatHandlerConfig(code_action.ActionHandlerConfig):
         # Literal["PY33", "PY34", "PY35", "PY36", "PY37",
         # "PY38", "PY39", "PY310", "PY311", "PY312"]
         str
-    ] = []
+    ] = dataclasses.field(default_factory=list)
     # default black line length is 88:
     # https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#line-length
     line_length: int = 88