Update release notes for version 1.3.0

Updated release date and added new features in version 1.3.0.

Author: MattB-msft

changelog.md

@@ -1,6 +1,6 @@
 # Microsoft 365 Agents SDK for .NET - Release Notes v1.3.0
 
-**Release Date:** October 22, 2025  
+**Release Date:** November 15, 2025  
 **Previous Version:** 1.2.0 (Released August 18, 2025)
 
 ## 🎉 What's New in 1.3.0
@@ -43,6 +43,9 @@ This release introduces first-class A2A hosting (preview), and Copilot Studio Co
 
 ## 🔐 Authentication & Security Enhancements
 
+- Add support for Entra Agent ID Preview
+- Improved Multi-tenant detction for authenticaiton token support this will attempt to create a tenant specifice token for User Autheitcation and AgentID scenarios when the authority associated with current Agent identity is using the /common authority.5
+
 ## 🐛 Bug Fixes & Maintenance
 
 - Resolved failures when registering `IAgent` implementations via factories in multi-agent hosts. ([#418](https://github.com/microsoft/Agents-for-net/pull/418))