Update Package.swift

Author: STREGA

Package.swift

@@ -85,9 +85,9 @@ let package = Package(
 
                         settings.append(contentsOf: [
                             // MARK: Gate Engine options.
-                            .define("GATEENGINE_SUPPORTS_MULTIWINDOW", .when(platforms: [.macOS, .windows, .linux])),
                             .define("GATEENGINE_ENABLE_HOTRELOADING", .when(platforms: [.macOS, .windows, .linux])),
                             .define("GATEENGINE_WASI_UNSUPPORTED_HOST", .when(platforms: [.windows])),
+                            .define("GATEENGINE_PLATFORM_SINGLETHREADED", .when(platforms: [.wasi])),
                         ])
 
                         #if false