Remove unnecessary scope attribute

We are not using the attribute for codegen or at run-time, to just remove it.

src/Moq.StaticProxy/MockSourceGenerator.cs

@@ -40,12 +40,11 @@ protected override void OnExecute(GeneratorExecutionContext context, StuntDocume
                 receivers.OfType<RecursiveMockSyntaxReceiver>().FirstOrDefault() is var recursive)
             {
                 var generatorAttr = context.Compilation.GetTypeByMetadataName(generator.GeneratorAttribute.FullName!);
-                var scopeAttr = context.Compilation.GetTypeByMetadataName(typeof(SetupScopeAttribute).FullName!);
                 var moqmodule = context.Compilation.GetTypeByMetadataName("Moq.IMoq")!.ContainingModule;
                 var sdkmodule = context.Compilation.GetTypeByMetadataName(typeof(IMock).FullName!)!.ContainingModule;
 
                 // If we can't know what's the attribute that annotates mock generators, we can't do anything.
-                if (generatorAttr != null || scopeAttr != null)
+                if (generatorAttr != null)
                 {
                     foreach (var node in recursive.CandidateNodes)
                     {

src/Moq/SetupExtension.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.ComponentModel;
 
 namespace Moq
@@ -14,7 +14,6 @@ public static class SetupExtension
         /// <summary>
         /// Sets up the mock with the given void method call.
         /// </summary>
-        [SetupScope]
         public static ISetup Setup<T>(this T mock, Action<T> action)
         {
             using (new SetupScope())
@@ -27,7 +26,6 @@ public static ISetup Setup<T>(this T mock, Action<T> action)
         /// <summary>
         /// Sets up the mock with the given function.
         /// </summary>
-        [SetupScope]
         public static TResult Setup<T, TResult>(this T mock, Func<T, TResult> function)
         {
             using (new SetupScope())
@@ -41,7 +39,6 @@ public static TResult Setup<T, TResult>(this T mock, Func<T, TResult> function)
         /// access and set ref/out arguments. A code fix will automatically 
         /// generate a delegate with the right signature when using this overload.
         /// </summary>
-        [SetupScope]
         public static ISetup<TDelegate> Setup<TDelegate>(this object mock, TDelegate member)
             => new DefaultSetup<TDelegate>(member as Delegate ?? throw new ArgumentException(ThisAssembly.Strings.Setup.DelegateExpected));
 
@@ -53,7 +50,6 @@ public static ISetup<TDelegate> Setup<TDelegate>(this object mock, TDelegate mem
         /// and pass in the method group directly instead. A code fix will automatically 
         /// generate a delegate with the right signature when using this overload.
         /// </summary>
-        [SetupScope]
         public static ISetup<TDelegate> Setup<TDelegate>(this object mock, Func<TDelegate> memberFunction)
         {
             using (new SetupScope())