DOC Update changelog before the 1.2.1 release (scikit-learn#25436)

doc/whats_new/v1.2.rst

@@ -22,6 +22,20 @@ random sampling procedures.
   into account.
   :pr:`25354` by :user:`Jérémie du Boisberranger <jeremiedbb>`.
 
+- |Fix| The `categories_` attribute of :class:`preprocessing.OneHotEncoder` now
+  always contains an array of `object`s when using predefined categories that
+  are strings. Predefined categories encoded as bytes will no longer work
+  with `X` encoded as strings. :pr:`25174` by :user:`Tim Head <betatim>`.
+
+Changes impacting all modules
+-----------------------------
+
+- |Fix| Support `pandas.Int64` dtyped `y` for classifiers and regressors.
+  :pr:`25089` by :user:`Tim Head <betatim>`.
+
+- |Fix| Remove spurious warnings for estimators internally using neighbors search methods.
+  :pr:`25129` by :user:`Julien Jerphanion <jjerphan>`.
+
 Changelog
 ---------
 
@@ -64,6 +78,12 @@ Changelog
   and :class:`ensemble.ExtraTreesRegressor` now support sparse readonly datasets.
   :pr:`25341` by :user:`Julien Jerphanion <jjerphan>`
 
+:mod:`sklearn.feature_extraction`
+.................................
+
+- |Fix| :class:`feature_extraction.FeatureHasher` raises an informative error
+  when the input is a list of strings. :pr:`25094` by `Thomas Fan`_.
+
 :mod:`sklearn.linear_model`
 ...........................
 
@@ -78,6 +98,20 @@ Changelog
 - |Fix| :class:`manifold.TSNE` now works correctly when output type is
   set to pandas :pr:`25370` by :user:`Tim Head <betatim>`.
 
+:mod:`sklearn.model_selection`
+..............................
+
+- |Fix| :func:`model_selection.cross_validate` with multimetric scoring in
+  case of some failing scorers the non-failing scorers now returns proper
+  scores instead of `error_score` values.
+  :pr:`23101` by :user:`András Simon <simonandras>` and `Thomas Fan`_.
+
+:mod:`sklearn.neural_network`
+.............................
+
+- |Fix| :class:`neural_network.MLPClassifier` and :class:`neural_network.MLPRegressor`
+  no longer raise warnings when fitting data with feature names.
+  :pr:`24873` by :user:`Tim Head <betatim>`.
 
 :mod:`sklearn.preprocessing`
 ............................