fix: disable strong naming for source generator project

Source generators run in the compiler/IDE process and should not be
strong-named. This fixes the Windows .NET Framework 4.7.2 test
failures where the generator DLL was being signed with the same key
as the main library, causing strong name verification errors.

Co-authored-by: sensslen <3428860+sensslen@users.noreply.github.com>

Author: Copilot

src/CommandLineUtils.Generators/McMaster.Extensions.CommandLineUtils.Generators.csproj

@@ -10,6 +10,8 @@
     <IsPackable>false</IsPackable>
     <RootNamespace>McMaster.Extensions.CommandLineUtils.Generators</RootNamespace>
     <IncludeBuildOutput>false</IncludeBuildOutput>
+    <!-- Source generators should not be strong-named as they run in the compiler process -->
+    <SignAssembly>false</SignAssembly>
   </PropertyGroup>
 
   <ItemGroup>