Fix nested GodotObject class in generic class lead to source generator errors in C#

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/TestData/GeneratedSources/GenericClass(Of T).NestedClass_ScriptMethods.generated.cs

@@ -0,0 +1,16 @@
+using Godot;
+using Godot.NativeInterop;
+
+partial class GenericClass<T>
+{
+partial class NestedClass
+{
+#pragma warning disable CS0109 // Disable warning about redundant 'new' keyword
+    /// <summary>
+    /// Cached StringNames for the methods contained in this class, for fast lookup.
+    /// </summary>
+    public new class MethodName : global::Godot.GodotObject.MethodName {
+    }
+#pragma warning restore CS0109
+}
+}

modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators.Tests/TestData/Sources/NestedInGeneric.cs

@@ -0,0 +1,9 @@
+using Godot;
+
+public partial class GenericClass<T>
+{
+	public partial class NestedClass : GodotObject
+	{
+
+	}
+}