Does the XUnit demo project need to use ConfigureAwait?

We're getting a load of warnings from Roslynator about missing `ConfigureAwait` calls in the Xunit.Demo project.

We need to determine whether they are in fact unneeded (e.g., as in most ASP.NET Core projects) and we should therefore surpress the message, or if they are in fact required.

Start by reviewing the Xunit.Demo project and the Roslynator warnings for missing ConfigureAwait calls. Determine whether ConfigureAwait is required in this project, using the ASP.NET Core comparison in the issue as context. Done means reaching a decision and either suppressing the warning or addressing the required calls.

Written by the indexing model from the issue text.