stm32: update changelog

Author: xoviat

embassy-stm32/CHANGELOG.md

@@ -38,6 +38,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - fix: usart: fix race condition in ringbuffered usart
 - feat: stm32/fdcan: add ability to control automatic recovery from bus off ([#4821](https://github.com/embassy-rs/embassy/pull/4821))
 - low-power: update rtc api to allow reconfig
+- adc: consolidate ringbuffer
 
 ## 0.4.0 - 2025-08-26