Update NUnit3TestAdapter to support net7.0 (Azure#31366)

Fixes Azure#31365

Author: heaths

eng/Packages.Data.props

@@ -245,7 +245,7 @@
     <PackageReference Update="Newtonsoft.Json" Version="10.0.3" />
     <PackageReference Update="NSubstitute" Version="3.1.0" />
     <PackageReference Update="NUnit" Version="3.13.2" />
-    <PackageReference Update="NUnit3TestAdapter" Version="4.2.1" />
+    <PackageReference Update="NUnit3TestAdapter" Version="4.3.0-alpha-net7.4" />
     <PackageReference Update="OpenTelemetry.Extensions.Hosting" Version="1.0.0-rc9.3" />
     <PackageReference Update="OpenTelemetry.Instrumentation.AspNetCore" Version="1.0.0-rc9.3" />
     <PackageReference Update="OpenTelemetry.Instrumentation.Http" Version="1.0.0-rc9.3" />