DOC: update DataFrame.to_csv write modes (pandas-dev#51839)

Remove the 'b' and 't' modes from the description.

Author: HamidrezaSK

pandas/core/generic.py

@@ -3643,9 +3643,6 @@ def to_csv(
             - 'x', open for exclusive creation, failing if the file already exists.
             - 'a', open for writing, appending to the end of file if it exists.
 
-            Including 'b' or 't' in the mode parameter will inform Pandas whether
-            `path_or_buf` requires string or binary data. However, in most cases,
-            this should not be necessary.
         encoding : str, optional
             A string representing the encoding to use in the output file,
             defaults to 'utf-8'. `encoding` is not supported if `path_or_buf`