fix: Disable TLS 1.3 on URLSessionHTTPClient (#766)

Author: jbelkins

Sources/ClientRuntime/Networking/Http/URLSession/URLSessionConfiguration+HTTPClientConfiguration.swift

@@ -17,6 +17,7 @@ extension URLSessionConfiguration {
         config.httpShouldSetCookies = false
         config.httpCookieAcceptPolicy = .never
         config.httpCookieStorage = nil
+        config.tlsMaximumSupportedProtocolVersion = .TLSv12
         return config
     }
 }