Changed target frameworks in `EnvelopeGenerator.GeneratorAPI.csproj` to only `net9.0`. Removed unused `using System.Reflection;` directive in `Program.cs` to streamline the code.
Changed target frameworks in `EnvelopeGenerator.GeneratorAPI.csproj` to only `net9.0`. Removed unused `using System.Reflection;` directive in `Program.cs` to streamline the code.