Prepare 2025.9 release

Author: hugovk

CHANGELOG.rst

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+`2025.9 <https://github.com/python/python-docs-theme/releases/tag/2025.9>`_
+---------------------------------------------------------------------------
+
+* Enable theme translation by @StanFromIreland in https://github.com/python/python-docs-theme/pull/246
+* Add Swedish translation by @yeager in https://github.com/python/python-docs-theme/pull/250
+* Pull Brazilian Portuguese, Simplified Chinese, Traditional Chinese translations from Transifex by @StanFromIreland in https://github.com/python/python-docs-theme/pull/253
+
 `2025.5 <https://github.com/python/python-docs-theme/releases/tag/2025.5>`_
 ---------------------------------------------------------------------------