added 'whatsnew'

Author: anmyachev

doc/source/whatsnew/v0.25.0.rst

@@ -269,6 +269,8 @@ Datetimelike
 - Bug in :class:`DataFrame` and :class:`Series` where timezone aware data with ``dtype='datetime64[ns]`` was not cast to naive (:issue:`25843`)
 - Improved :class:`Timestamp` type checking in various datetime functions to prevent exceptions when using a subclassed ``datetime`` (:issue:`25851`)
 - Bug in :class:`Series` and :class:`DataFrame` repr where ``np.datetime64('NaT')`` and ``np.timedelta64('NaT')`` with ``dtype=object`` would be represented as ``NaN`` (:issue:`25445`)
+- Bug in :func:`to_datetime` which would raise ``InvalidIndexError: Reindexing only valid with uniquely valued Index objects`` when called with ``cache=True``, with ``arg`` including at least two different elements from the set {None, numpy.nan, pandas.NaT} (:issue:`22305`)
+- Bug in :func:`to_datetime` which would raise ``ValueError: Tz-aware datetime.datetime cannot be converted to datetime64 unless utc=True`` when called with ``cache=True``, with ``arg`` including datetime strings with different offset (:issue:`26097`)
 -
 
 Timedelta