DOC: whatsnew entry for on_bad_lines regression fix (GH#61837)

Author: skalwaghe-56

doc/source/whatsnew/v2.3.3.rst

@@ -24,6 +24,8 @@ Bug fixes
 ^^^^^^^^^
 - Fix regression in ``~Series.str.contains``, ``~Series.str.match`` and ``~Series.str.fullmatch``
   with a compiled regex and custom flags (:issue:`62240`)
+- Fix regression in ``on_bad_lines`` callable when returning too many fields: now emits
+  ``ParserWarning`` and truncates extra fields regardless of ``index_col`` (:issue:`61837`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_233.contributors: