arc: Fixup availability

Author: simonjbeaumont

Sources/_CryptoExtras/ARC/ARCEncoding.swift

@@ -14,7 +14,7 @@
 import Foundation
 import Crypto
 
-@available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, macCatalyst 13, visionOS 1.0, *)
+@available(macOS 10.15, iOS 13.2, tvOS 13.2, watchOS 6.1, macCatalyst 13.2, visionOS 1.2, *)
 typealias ARCP256 = HashToCurveImpl<P256>
 @available(macOS 10.15, iOS 13.2, tvOS 13.2, watchOS 6.1, macCatalyst 13.2, visionOS 1.2, *)
 typealias ARCP384 = HashToCurveImpl<P384>