Add .NET 9.0 to Tests

Author: sdrapkin

SecurityDriven.Core.Tests/SecurityDriven.Core.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net8.0;net7.0;net6.0;net5.0</TargetFrameworks>
+    <TargetFrameworks>net9.0;net8.0;net7.0;net6.0;net5.0</TargetFrameworks>
 
     <IsPackable>false</IsPackable>
 		<DisableImplicitNamespaceImports>true</DisableImplicitNamespaceImports>