Bump Microsoft.AspNetCore.Mvc.NewtonsoftJson (#3935)

Bumps [Microsoft.AspNetCore.Mvc.NewtonsoftJson](https://github.com/aspnet/AspNetCore) from 3.1.8 to 3.1.9.
- [Release notes](https://github.com/aspnet/AspNetCore/releases)
- [Commits](dotnet/aspnetcore@v3.1.8...v3.1.9)

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

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

Author: dependabot[bot]

core/diagnostics/DiagnosticScenarios/DiagnosticScenarios.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.8" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.9" />
   </ItemGroup>
 
 </Project>