Fix NET8 build

Directory.Build.targets

@@ -1,5 +1,5 @@
 <Project>
-  <PropertyGroup Condition="$(NETCoreSdkVersion.StartsWith('7.0'))">
+  <PropertyGroup Condition="$([MSBuild]::VersionGreaterThanOrEquals($(NETCoreSdkVersion), '7.0'))">
     <DefineConstants>$(DefineConstants);NET7SDK</DefineConstants>
   </PropertyGroup>  
 </Project>