[3.13] gh-123441: Correct the supported languages of the iso-8859-4 codec (GH-137034) (GH-137418)

(cherry picked from commit 525784a)

Co-authored-by: Stan Ulbrych <[email protected]>

Author: miss-islington

Doc/library/codecs.rst

@@ -1243,7 +1243,7 @@ particular, the following variants typically exist:
 +-----------------+--------------------------------+--------------------------------+
 | iso8859_3       | iso-8859-3, latin3, L3         | Esperanto, Maltese             |
 +-----------------+--------------------------------+--------------------------------+
-| iso8859_4       | iso-8859-4, latin4, L4         | Baltic languages               |
+| iso8859_4       | iso-8859-4, latin4, L4         | Northern Europe                |
 +-----------------+--------------------------------+--------------------------------+
 | iso8859_5       | iso-8859-5, cyrillic           | Belarusian, Bulgarian,         |
 |                 |                                | Macedonian, Russian, Serbian   |