[iOS][swift] move SpineiOS target behind SpineiOSWrapper which gates platform condition, so that the library user won't get compiler crash on non iOS target (macOS) (#2970)

Author: pbk20191

Package.swift

@@ -25,10 +25,17 @@ let package = Package(
         ),
         .library(
             name: "SpineiOS",
-            targets: ["SpineiOS"]
+            targets: ["SpineiOSWrapper"]
         ),
     ],
     targets: [
+        .target(
+            name: "SpineiOSWrapper",
+            dependencies: [
+                .target(name: "SpineiOS", condition: .when(platforms: [.iOS, .visionOS, .tvOS, .macCatalyst ]))
+            ],
+            path: "spine-ios/Sources/SpineiOSWrapper"
+        ),
         .target(
             name: "SpineiOS",
             dependencies: [

spine-ios/Sources/SpineiOSWrapper/stub.swift

@@ -0,0 +1,7 @@
+//
+//  stub.swift
+//  spine-ios
+//
+//  Created by pbk20191 on 11/7/25.
+//
+