Fix unecessary IDE0060 suppressions (#105036)

Since dotnet/roslyn#66535 `IDE0060` doesn't warn for throw-only methods.

Author: xtqqczze

src/coreclr/System.Private.CoreLib/src/Internal/Runtime/InteropServices/ComActivator.PlatformNotSupported.cs

@@ -4,8 +4,6 @@
 using System;
 using System.Runtime.InteropServices;
 
-#pragma warning disable IDE0060
-
 namespace Internal.Runtime.InteropServices
 {
     internal static class ComActivator

src/coreclr/System.Private.CoreLib/src/Internal/Runtime/InteropServices/InMemoryAssemblyLoader.PlatformNotSupported.cs

@@ -2,10 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Runtime.InteropServices;
-using System.Runtime.Loader;
-
-#pragma warning disable IDE0060
 
 namespace Internal.Runtime.InteropServices
 {

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.NativeAot.cs

@@ -27,7 +27,6 @@ public static void InitializeArray(Array array, RuntimeFieldHandle fldHandle)
             throw new PlatformNotSupportedException();
         }
 
-#pragma warning disable IDE0060
         private static unsafe ref byte GetSpanDataFrom(
             RuntimeFieldHandle fldHandle,
             RuntimeTypeHandle targetTypeHandle,
@@ -39,7 +38,6 @@ private static unsafe ref byte GetSpanDataFrom(
             // https://github.com/dotnet/corert/issues/364
             throw new PlatformNotSupportedException();
         }
-#pragma warning disable IDE0060
 
         [RequiresUnreferencedCode("Trimmer can't guarantee existence of class constructor")]
         public static void RunClassConstructor(RuntimeTypeHandle type)

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.Com.cs

@@ -373,12 +373,10 @@ public static int GetEndComSlot(Type t)
             throw new NotSupportedException(SR.PlatformNotSupported_ComInterop);
         }
 
-#pragma warning disable IDE0060
         internal static Type? GetTypeFromCLSID(Guid clsid, string? server, bool throwOnError)
         {
             throw new NotSupportedException(SR.PlatformNotSupported_ComInterop);
         }
-#pragma warning restore
 
         [SupportedOSPlatform("windows")]
         public static string GetTypeInfoName(ITypeInfo typeInfo)

src/libraries/System.Private.CoreLib/src/System/IO/Directory.Windows.cs

@@ -8,10 +8,8 @@ namespace System.IO
 {
     public static partial class Directory
     {
-#pragma warning disable IDE0060
         private static DirectoryInfo CreateDirectoryCore(string path, UnixFileMode unixCreateMode)
             => throw new PlatformNotSupportedException(SR.PlatformNotSupported_UnixFileMode);
-#pragma warning restore IDE0060
 
         private static unsafe string CreateTempSubdirectoryCore(string? prefix)
         {

src/libraries/System.Private.CoreLib/src/System/IO/File.Windows.cs

@@ -7,7 +7,6 @@ namespace System.IO
 {
     public static partial class File
     {
-#pragma warning disable IDE0060
         private static UnixFileMode GetUnixFileModeCore(string path)
             => throw new PlatformNotSupportedException(SR.PlatformNotSupported_UnixFileMode);
 
@@ -19,6 +18,5 @@ private static void SetUnixFileModeCore(string path, UnixFileMode mode)
 
         private static void SetUnixFileModeCore(SafeFileHandle fileHandle, UnixFileMode mode)
             => throw new PlatformNotSupportedException(SR.PlatformNotSupported_UnixFileMode);
-#pragma warning restore IDE0060
     }
 }

src/libraries/System.Private.CoreLib/src/System/IO/FileSystem.Unix.cs

@@ -62,7 +62,6 @@ public static void CopyFile(string sourceFullPath, string destFullPath, bool ove
             return null; // Let SafeFileHandle create the exception for this error.
         }
 
-#pragma warning disable IDE0060
         public static void Encrypt(string path)
         {
             throw new PlatformNotSupportedException(SR.PlatformNotSupported_FileEncryption);
@@ -72,7 +71,6 @@ public static void Decrypt(string path)
         {
             throw new PlatformNotSupportedException(SR.PlatformNotSupported_FileEncryption);
         }
-#pragma warning restore IDE0060
 
         private static void LinkOrCopyFile (string sourceFullPath, string destFullPath)
         {

src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/Unsafe.cs

@@ -1,8 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#pragma warning disable IDE0060 // implementations provided as intrinsics
-using System;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.Versioning;

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/PosixSignalRegistration.PlatformNotSupported.cs

@@ -9,11 +9,9 @@ public sealed partial class PosixSignalRegistration
     {
         private PosixSignalRegistration() { }
 
-#pragma warning disable IDE0060
         [DynamicDependency("#ctor")] // Prevent the private ctor and the IDisposable implementation from getting linked away
         private static PosixSignalRegistration Register(PosixSignal signal, Action<PosixSignalContext> handler) =>
             throw new PlatformNotSupportedException();
-#pragma warning restore IDE0060
 
         partial void Unregister();
     }

src/libraries/System.Private.CoreLib/src/System/Runtime/Intrinsics/Arm/Aes.PlatformNotSupported.cs

@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#pragma warning disable IDE0060 // unused parameters
 using System.Runtime.CompilerServices;
 
 namespace System.Runtime.Intrinsics.Arm