build (targets): import version properties from external path

Ensures version information is loaded from an external props file when available.
Improves consistency of version handling across local and CI builds.

Author: framinosona

Plugin.ExceptionListeners.Maui/Directory.Build.targets

@@ -28,6 +28,7 @@
   </Target>
 
   <!-- ==================== VERSION ==================== -->
+  <Import Project="$(Version_Props_Path)" Condition="Exists('$(Version_Props_Path)')" />
   <PropertyGroup>
     <!-- Default version, when building locally -->
     <Version_Full Condition=" '$(Version_Full)' == '' ">1.0.0</Version_Full>