Address Copilot review comments in PR 4259

Author: paulmedynski

build.proj

@@ -404,7 +404,7 @@
     the first step of this target.
   -->
   <PropertyGroup>
-    <BuildSqlClientNotSupportedDependsOn Condition="'$(ReferenceType.ToLower())' == 'package'">PackAbstractions</BuildSqlClientNotSupportedDependsOn>
+    <BuildSqlClientNotSupportedDependsOn Condition="'$(ReferenceType.ToLower())' == 'package'">PackAbstractions;PackSqlServer</BuildSqlClientNotSupportedDependsOn>
   </PropertyGroup>
   <Target Name="BuildSqlClientNotSupported" DependsOnTargets="$(BuildSqlClientNotSupportedDependsOn)">
     <PropertyGroup>

src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft.Data.SqlClient.UnitTests.csproj

@@ -47,7 +47,7 @@
     <ProjectReference Include="$(RepoRoot)src/Microsoft.SqlServer.Server/Microsoft.SqlServer.Server.csproj" />
   </ItemGroup>
 
-  <Target Name="ValidateReferenceType" BeforeTargets="Restore"
+  <Target Name="ValidateReferenceType" BeforeTargets="Restore;PrepareForBuild"
           Condition="'$(ReferenceType)' == 'Package'">
     <Error Text="Microsoft.Data.SqlClient.UnitTests.csproj does not support ReferenceType=Package. Use project references for unit tests." />
   </Target>