update release_notes (#435)

Co-authored-by: Jonas Israel <[email protected]>

Author: Jonas-Isr

docs/release_notes.md

@@ -13,6 +13,7 @@
 ### ✨ New Functionality
 
 - [Orchestration] Added new model DeepSeek-R1: `OrchestrationAiModel.DEEPSEEK_R1`
+- [Orchestration] [Tool execution fully enabled](https://sap.github.io/ai-sdk/docs/java/spring-ai/orchestration#tool-calling)
 
 ### 📈 Improvements