[Bug]: CS8615 for generated nullable event mocks

[Kaskadee]

Description

The nullability of event members in an interface is ignored in the generated mock implementation causing the warning CS8615: Nullability of reference types in type doesn't match implemented member 'event EventHandler<string>? IFoo.Something'

public sealed class IFooMock : global::TUnit.Mocks.Mock<global::Sandbox.IFoo>, global::Sandbox.IFoo
{
    [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
    internal IFooMock(global::Sandbox.IFoo mockObject, global::TUnit.Mocks.MockEngine<global::Sandbox.IFoo> engine)
        : base(mockObject, engine) { }

    event global::System.EventHandler<string> global::Sandbox.IFoo.Something { add => Object.Something += value; remove => Object.Something -= value; } // Should be `EventHandler<string>?` instead.
}

Expected Behavior

The generated event should use the same nullability as declared in the interface

Actual Behavior

The generated event is non-nullable even though it is declared as nullable in the interface

Steps to Reproduce

using TUnit.Mocks.Generated.Sandbox;

namespace Sandbox;

public interface IFoo {
    event EventHandler<string>? Something;
}

public class TestClass {
    [Test]
    public async Task SomeTest() {
        IFooMock foo = IFoo.Mock();
    }
}

TUnit Version

1.28.7-beta

.NET Version

.NET 10.0

Operating System

Windows

IDE / Test Runner

JetBrains Rider

Error Output / Stack Trace

Restore complete (1.3s)
  Sandbox net10.0 succeeded with 1 warning(s) (1.8s) → Sandbox/bin/Debug/net10.0/Sandbox.dll
    /mnt/x/Sandbox/Sandbox/obj/Debug/net10.0/TUnit.Mocks.SourceGenerator/TUnit.Mocks.SourceGenerator.MockGenerator/Sandbox_IFoo_Mock.g.cs(12,72): warning CS8615: Nullability of reference types in type doesn't match implemented member 'event EventHandler<string>? IFoo.Something'.

Build succeeded with 1 warning(s) in 3.6s

Additional Context

No response

IDE-Specific Issue?

• I've confirmed this issue occurs when running via dotnet test or dotnet run, not just in my IDE