Get rid of TeamCity.VSTest.TestAdapter

* New version of TeamCity isn't compatible with the old TeamCity.VSTest.TestAdapter, so deiced to remove it, because new .NET runners are used which override reason of using TeamCity.VSTest.TestAdapter

Author: introfog

itext.tests/itext.cleanup.tests/itext.cleanup.tests.csproj

@@ -23,7 +23,6 @@
         <AssemblyName>itext.cleanup.tests</AssemblyName>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="TeamCity.VSTest.TestAdapter" Version="1.0.0" />
         <PackageReference Include="NUnit" Version="3.7.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.8.0" />
     </ItemGroup>