build(macOS): re-add macOS in the package but error if it's built for it

Author: renaudjenny

Package.swift

@@ -5,7 +5,7 @@ import PackageDescription
 
 let package = Package(
     name: "swift-tts",
-    platforms: [.iOS(.v15)],
+    platforms: [.iOS(.v15), .macOS(.v13)],
     products: [
         .library(name: "SwiftTTS", targets: ["SwiftTTS"]),
         .library(name: "SwiftTTSDependency", targets: ["SwiftTTSDependency"]),

Sources/SwiftTTS/SwiftTTS.swift

@@ -1,3 +1,7 @@
+#if os(macOS)
+#error("This library is not compatible with macOS")
+#endif
+
 import AVFoundation
 
 public struct SwiftTTS {

Sources/SwiftTTSCombine/SwiftTTSCombine.swift

@@ -1,3 +1,7 @@
+#if os(macOS)
+#error("This library is not compatible with macOS")
+#endif
+
 import Foundation
 import Combine
 import AVFoundation

Sources/SwiftTTSDependency/SwiftTTSDependency.swift

@@ -1,3 +1,7 @@
+#if os(macOS)
+#error("This library is not compatible with macOS")
+#endif
+
 import AVFoundation
 import Dependencies
 import SwiftTTS

Tests/SwiftTTSTests/SwiftTTSTests.swift

@@ -1,3 +1,7 @@
+#if os(macOS)
+#error("This library is not compatible with macOS")
+#endif
+
 import AVFoundation
 import SwiftTTS
 import XCTest