Bump the dotnet group with 1 update

Bumps Microsoft.Extensions.AI from 9.9.0 to 9.9.1

---
updated-dependencies:
- dependency-name: Microsoft.Extensions.AI
  dependency-version: 9.9.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dotnet
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/ai/quickstarts/snippets/structured-output/SOChat.csproj

@@ -11,7 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Azure.AI.OpenAI" Version="2.1.0" />
     <PackageReference Include="Azure.Identity" Version="1.16.0" />
-    <PackageReference Include="Microsoft.Extensions.AI" Version="9.9.0" />
+    <PackageReference Include="Microsoft.Extensions.AI" Version="9.9.1" />
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="9.4.0-preview.1.25207.5" />
     <PackageReference Include="Microsoft.Extensions.Configuration" Version="9.0.9" />
     <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="9.0.9" />