Bump Microsoft.AspNetCore.Mvc.NewtonsoftJson (#42)

Bumps [Microsoft.AspNetCore.Mvc.NewtonsoftJson](https://github.com/aspnet/AspNetCore) from 3.0.0-preview3-19153-02 to 3.0.0-preview5-19227-01.
- [Release notes](https://github.com/aspnet/AspNetCore/releases)
- [Changelog](https://github.com/aspnet/AspNetCore/blob/master/docs/CrossRepoBreakingChanges.md)
- [Commits](https://github.com/aspnet/AspNetCore/compare/v3.0.0-preview3-19153-02...v3.0.0-preview5-19227-01)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

razor/ReactiveUI.RazorExample/ReactiveUI.RazorExample.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Components.Server" Version="3.0.0-preview3-19153-02" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0-preview3-19153-02" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0-preview5-19227-01" />
     <PackageReference Include="ReactiveUI" Version="9.18.2" />
     <PackageReference Include="ReactiveUI.Fody" Version="9.18.2" />
   </ItemGroup>