Bump HotChocolate from 13.9.11 to 13.9.12 in /src

Bumps [HotChocolate](https://github.com/ChilliCream/graphql-platform) from 13.9.11 to 13.9.12.
- [Release notes](https://github.com/ChilliCream/graphql-platform/releases)
- [Commits](ChilliCream/graphql-platform@13.9.11...13.9.12)

---
updated-dependencies:
- dependency-name: HotChocolate
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

src/Fluss.HotChocolate/Fluss.HotChocolate.csproj

@@ -8,7 +8,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="HotChocolate" Version="13.9.11" />
+        <PackageReference Include="HotChocolate" Version="13.9.12" />
         <PackageReference Include="HotChocolate.AspNetCore" Version="13.9.11" />
         <PackageReference Include="HotChocolate.Data" Version="13.9.11" />
     </ItemGroup>