[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.

Author: jsquire

CHANGELOG.md

@@ -1,5 +1,11 @@
 # 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. 
+
 ## 2.2.0 (2025-07-02)
 
 ### Features Added

src/OpenAI.csproj

@@ -81,7 +81,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
-    <PackageReference Include="System.ClientModel" Version="1.4.2" />
+    <PackageReference Include="System.ClientModel" Version="1.5.1" />
   </ItemGroup>
 
   <ItemGroup Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net6.0'))">