Revert "Use correct ISO 8601 date decoder"

This reverts commit 5da357ee9c.

Pachyderm/Client.swift

@@ -28,7 +28,11 @@ public class Client {
     
     lazy var decoder: JSONDecoder = {
         let decoder = JSONDecoder()
-        decoder.dateDecodingStrategy = .iso8601
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SZ"
+        formatter.timeZone = TimeZone(abbreviation: "UTC")
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        decoder.dateDecodingStrategy = .formatted(formatter)
         return decoder
     }()