Fix for macCatalyst

Author: Daniel Sincere

SwiftDraw/Sources/CanvasNSView.swift

@@ -29,7 +29,7 @@
 //  3. This notice may not be removed or altered from any source distribution.
 //
 
-#if canImport(AppKit)
+#if canImport(AppKit) && !targetEnvironment(macCatalyst)
 import AppKit
 import SwiftUI