Remove condition on the import of VisualStudio.targets

This condition has the side effect of changing the packages that we
depend on, depending on the type of MSBuild used to restore packages.
This is because VisualStudio.targets iself contains PackageReferences.
This can cause all sorts of slowdowns when restore needs to rerun a lot.

Author: jasonmalinowski

src/Microsoft.DotNet.Arcade.Sdk/tools/Imports.targets

@@ -15,7 +15,7 @@
 
   <Import Project="Performance.targets" Condition="'$(DisableArcadeTestFramework)' != 'true'" />
   <Import Project="Localization.targets" />
-  <Import Project="VisualStudio.targets" Condition="'$(UsingToolVSSDK)' == 'true' and ('$(IsVsixProject)' == 'true' or '$(IsSwixProject)' == 'true' or '$(GeneratePkgDefFile)' == 'true') and '$(MSBuildRuntimeType)' != 'Core'"/>
+  <Import Project="VisualStudio.targets" Condition="'$(UsingToolVSSDK)' == 'true' and ('$(IsVsixProject)' == 'true' or '$(IsSwixProject)' == 'true' or '$(GeneratePkgDefFile)' == 'true')"/>
   <Import Project="OptimizationData.targets" Condition="'$(UsingToolIbcOptimization)' == 'true'"/>
   <Import Project="SymStore.targets" Condition="'$(ContinuousIntegrationBuild)' == 'true' and '$(OS)' == 'Windows_NT'"/>