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.html2pdf.tests/itext.html2pdf.tests.csproj

@@ -27,7 +27,6 @@
     <AssemblyName>itext.html2pdf.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>