DOC Fix broken formatting of cohen_kappa_score docstring (scikit-learn#31732)

Author: StefanieSenger

sklearn/metrics/_classification.py

@@ -831,8 +831,8 @@ class labels [2]_.
         List of labels to index the matrix. This may be used to select a
         subset of labels. If `None`, all labels that appear at least once in
         ``y1`` or ``y2`` are used. Note that at least one label in `labels` must be
-         present in `y1`, even though this function is otherwise agnostic to the order
-         of `y1` and `y2`.
+        present in `y1`, even though this function is otherwise agnostic to the order
+        of `y1` and `y2`.
 
     weights : {'linear', 'quadratic'}, default=None
         Weighting type to calculate the score. `None` means not weighted;