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/snippets/microsoft-extensions-ai/AI.Shared/AI.Shared.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.AI" Version="9.9.0" />
+    <PackageReference Include="Microsoft.Extensions.AI" Version="9.9.1" />
     <PackageReference Include="System.Threading.RateLimiting" Version="10.0.0-rc.1.25451.107" />
   </ItemGroup>