Update project version to 4.2.0-alpha

Upgraded the version from 4.1.0-alpha to 4.2.0-alpha in Directory.Build.props. This change keeps the project versioning current and in alignment with recent enhancements.

src/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
     <PropertyGroup>
-        <Version>4.1.0-alpha</Version>
+        <Version>4.2.0-alpha</Version>
         <TargetFrameworks>net6.0;net7.0;net8.0</TargetFrameworks>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>