chore: more generic datetime selection

Author: xmatthias

freqtrade/rpc/rpc.py

@@ -1546,7 +1546,7 @@ def _convert_dataframe_to_dict(
 
             # band-aid until this is fixed:
             # https://github.com/pandas-dev/pandas/issues/45836
-            datetime_types = ["datetime", "datetime64", "datetime64[ns, UTC]"]
+            datetime_types = ["datetime", "datetime64", "datetimetz"]
             date_columns = dataframe.select_dtypes(include=datetime_types)
             for date_column in date_columns:
                 # replace NaT with `None`