Remove System.Threading.Tasks.Extensions package reference closes #683

Author: milkshakeuk

tests/NHapi.Base.NUnit/NHapi.Base.NUnit.csproj

@@ -43,8 +43,6 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <!-- can remove this with next version of nunit https://github.com/nunit/nunit/pull/4582 -->
-    <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.6.2" />
   </ItemGroup>
 
 </Project>