llama.swiftui : use llama.cpp as SPM package (#4804)

examples/llama.swiftui/llama.cpp.swift/LibLlama.swift

@@ -1,8 +1,5 @@
 import Foundation
-
-// To use this in your own project, add llama.cpp as a swift package dependency
-// and uncomment this import line.
-// import llama
+import llama
 
 enum LlamaError: Error {
     case couldNotInitializeContext

examples/llama.swiftui/llama.cpp.swift/bridging-header.h

@@ -1,5 +0,0 @@
-//
-//  Use this file to import your target's public headers that you would like to expose to Swift.
-//
-
-#import "llama.h"