Modernize Visual Studio AddIn csproj part 1: Remove duplicate constant definitions and use Microsoft.VSSDK.BuildTools instead of defining VSToolsPath manually.

ILSpy.AddIn/ILSpy.AddIn.csproj

@@ -2,9 +2,6 @@
 <Project>
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
 
-  <PropertyGroup>
-    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
-  </PropertyGroup>
 
   <PropertyGroup>
     <TargetFramework>net472</TargetFramework>
@@ -18,6 +15,7 @@
 
     <EnableDefaultItems>False</EnableDefaultItems>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <DefineConstants>TRACE;VSADDIN</DefineConstants>
 
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>Key.snk</AssemblyOriginatorKeyFile>
@@ -50,6 +48,7 @@
     <PackageReference Include="Microsoft.CodeAnalysis" Version="2.4.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="2.4.0" />
     <PackageReference Include="Microsoft.VisualStudio.LanguageServices" Version="2.4.0" />
+    <PackageReference Include="Microsoft.VSSDK.BuildTools" Version="16.8.3038" />
     <PackageReference Include="Mono.Cecil" Version="$(MonoCecilVersion)" />
   </ItemGroup>
 
@@ -202,14 +201,6 @@
     <UseCodebase>true</UseCodebase>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
-    <DefineConstants>TRACE;VSADDIN</DefineConstants>
-  </PropertyGroup>
-
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
-    <DefineConstants>TRACE;VSADDIN</DefineConstants>
-  </PropertyGroup>
-
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
 
   <Import Project="$(VSToolsPath)\VSSDK\Microsoft.VsSDK.targets" Condition="Exists('$(VSToolsPath)\VSSDK\Microsoft.VsSDK.targets')" />