[EnySys] Bump SCM Version to 1.5.1 (#539)

* [EnySys] Bump SCM Version to 1.5.1

The focus of these changes is to update
`System.ClientModel` to version 1.5.1, in order
to absorb a fix for a concurrency bug that can cause
infinite loops during deserialization on the legacy
.NET Framework.

* Updating context with new attribute

* Add explicity AsyncInterfaces reference for

* Remove net6 target

Author: jsquire

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Release History
 
+## 2.3.0-beta.1 (Unreleased)
+
+### Other changes
+
+- Updated to `System.ClientModel` 1.5.1, which contains a fix for a concurrency bug which could cause some applications running on the legacy .NET Framework to experience an infinite loop while deserializing service responses. 
+
+- Removed explicit `net6.0` target framework, as this version reached end-of-life in November, 2024 and is no longer maintained nor supported by Microsoft.  This does not prevent using the OpenAI library on .NET 6, as the runtime will fallback to the `netstandard2.0` target.
+
 ## 2.2.0 (2025-07-02)
 
 ### Features Added