docs: add breaking change to the changelog

Author: fpoy

user_guide_src/source/changelogs/v4.3.0.rst

@@ -89,6 +89,7 @@ The return value of  ``Validation::loadRuleGroup()`` has been changed ``null`` t
 Others
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+- The return type of ``CodeIgniter\Database\BasePreparedQuery::close()`` has been changed to ``bool``.
 - The return type of ``CodeIgniter\Database\Database::loadForge()`` has been changed to ``Forge``.
 - The return type of ``CodeIgniter\Database\Database::loadUtils()`` has been changed to ``BaseUtils``.
 - Parameter ``$column`` has changed in ``Table::dropForeignKey()`` to ``$foreignName``.