Update to dbup-core 6.0

Author: droyad

src/dbup-sqlserver/dbup-sqlserver.csproj

@@ -23,8 +23,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="dbup-core" Version="6.0.0-beta.146"/>
-    <PackageReference Include="System.Net.Security" Version="4.3.2" />
+    <PackageReference Include="dbup-core" Version="6.0.3"/>
     <PackageReference Include="Microsoft.Data.SqlClient" Version="5.2.2" />
   </ItemGroup>