Update Package.swift

Author: trilliwon

Package.swift

@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
     name: "libwebp",
     platforms: [
-        .macOS(.v10_10), .iOS(.v8), .tvOS(.v9), .watchOS(.v2)
+        .macOS(.v10_10), .iOS(.v9), .tvOS(.v9), .watchOS(.v2)
     ],
     products: [
         // Products define the executables and libraries produced by a package, and make them visible to other packages.