check namespace for null

[SimonCropp]

https://docs.microsoft.com/en-us/dotnet/api/system.type.namespace?view=net-6.0

Namespace: The namespace of the Type; null if the current instance has no namespace or represents a generic parameter.

System.NullReferenceException: Object reference not set to an instance of an object.

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.Playwright.Transport.Connection.WrapApiCallAsync[T](Func`1 action, Boolean isInternal) in /_/src/Playwright/Transport/Connection.cs:line 443
   at Microsoft.Playwright.Transport.Channels.Root.InitializeAsync() in /_/src/Playwright/Transport/Channels/Root.cs:line 47
   at Microsoft.Playwright.Playwright.CreateAsync() in /_/src/Playwright/Playwright.cs:line 52
   at PlaywrightFixture.InitializeAsync() in C:\Code\Verify.HeadlessBrowsers\src\Tests\PlaywrightFixture.cs:line 22
   at Xunit.Sdk.ExceptionAggregator.RunAsync(Func`1 code) in C:\Dev\xunit\xunit\src\xunit.core\Sdk\ExceptionAggregator.cs:line 90