📝 Update release notes

[skip ci]

docs/en/docs/release-notes.md

@@ -9,6 +9,7 @@ hide:
 
 ### Translations
 
+* 🌐 Add Japanese translation for `docs/ja/docs/environment-variables.md`. PR [#13226](https://github.com/fastapi/fastapi/pull/13226) by [@k94-ishi](https://github.com/k94-ishi).
 * 🌐 Add Russian translation for `docs/ru/docs/advanced/async-tests.md`. PR [#13227](https://github.com/fastapi/fastapi/pull/13227) by [@Rishat-F](https://github.com/Rishat-F).
 * 🌐 Update Russian translation for `docs/ru/docs/tutorial/dependencies/dependencies-in-path-operation-decorators.md`. PR [#13252](https://github.com/fastapi/fastapi/pull/13252) by [@Rishat-F](https://github.com/Rishat-F).
 * 🌐 Add Russian translation for `docs/ru/docs/tutorial/bigger-applications.md`. PR [#13154](https://github.com/fastapi/fastapi/pull/13154) by [@alv2017](https://github.com/alv2017).