[NFC] assign directly to self the parsed version, instead of calling init(_ version: Version)

Author: WowbaggersLiquidLunch

Sources/PackageDescription/Version+StringLiteralConvertible.swift

@@ -16,7 +16,7 @@ extension Version: ExpressibleByStringLiteral {
     ///     - version: A string literal to use for creating a new version struct.
     public init(stringLiteral value: String) {
         if let version = Version(value) {
-            self.init(version)
+            self = version
         } else {
             // If version can't be initialized using the string literal, report
             // the error and initialize with a dummy value. This is done to