Remove unnecessary using in security folder (#13861)

src/System.Management.Automation/security/CatalogHelper.cs

@@ -3,18 +3,12 @@
 
 #if !UNIX
 
-using Dbg = System.Management.Automation;
-using System;
-using System.Text;
 using System.Security.Cryptography;
 using System.Collections.Generic;
-using System.Collections;
 using System.Collections.ObjectModel;
-using System.ComponentModel;
 using System.IO;
 using System.Linq;
 using System.Management.Automation.Internal;
-using System.Management.Automation.Provider;
 using System.Management.Automation.Security;
 using System.Runtime.InteropServices;
 using DWORD = System.UInt32;

src/System.Management.Automation/security/MshSignature.cs

@@ -5,7 +5,6 @@ using System.ComponentModel;
 using System.Management.Automation.Internal;
 using System.Security.Cryptography.X509Certificates;
 
-using Dbg = System.Management.Automation;
 using DWORD = System.UInt32;
 
 namespace System.Management.Automation

src/System.Management.Automation/security/nativeMethods.cs

@@ -7,7 +7,6 @@
 using System.Runtime.InteropServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Management.Automation.Internal;
-using System.Runtime.ConstrainedExecution;
 using DWORD = System.UInt32;
 using BOOL = System.UInt32;
 

src/System.Management.Automation/security/wldpNativeMethods.cs

@@ -7,7 +7,6 @@
 #if !UNIX
 
 using System.Management.Automation.Internal;
-using Microsoft.Win32;
 using System.Runtime.InteropServices;
 using System.Diagnostics.CodeAnalysis;