Bump Anthropic from 12.8.0 to 12.9.0 (#1460)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -62,7 +62,7 @@
 
   <!-- Testing dependencies -->
   <ItemGroup>
-    <PackageVersion Include="Anthropic" Version="12.8.0" />
+    <PackageVersion Include="Anthropic" Version="12.9.0" />
     <PackageVersion Include="coverlet.collector" Version="8.0.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>