Fixed changelog entry placed in wrong section

The 3.4.0 version was already set when the entry was added; see
78bcd0e#diff-ff3c479edefad986d2fe6fe7ead575a46b086e3bbcf0ccc86d85efc4a4c63c79R8

CHANGES.rst

@@ -4,6 +4,8 @@ Changes
 Unreleased
 ----------
 
+- Fixed ``FieldError`` when creating historical records for many-to-many fields with
+  ``to="self"`` (gh-1218)
 - Allow ``HistoricalRecords.m2m_fields`` as str (gh-1243)
 - Fixed ``HistoryRequestMiddleware`` deleting non-existent
   ``HistoricalRecords.context.request`` in very specific circumstances (gh-1256)
@@ -36,8 +38,6 @@ Unreleased
   ``HistoricalRecords.context.request``) under some circumstances (gh-1188)
 - Made ``HistoryRequestMiddleware`` async-capable (gh-1209)
 - Fixed error when setting ``table_name`` with ``inherit=True`` (gh-1195)
-- Fixed ``FieldError`` when creating historical records for many-to-many fields with
-  ``to="self"`` (gh-1218)
 
 3.3.0 (2023-03-08)
 ------------------