bpo-40275: Move transient_internet from test.support to socket_helper (GH-19711)

diff --git a/Lib/test/test_timeout.py b/Lib/test/test_timeout.py
index c0952c7..ac803f5 100644
--- a/Lib/test/test_timeout.py
+++ b/Lib/test/test_timeout.py
@@ -20,7 +20,7 @@
     We must perform name resolution before timeout tests, otherwise it will be
     performed by connect().
     """
-    with support.transient_internet(host):
+    with socket_helper.transient_internet(host):
         return socket.getaddrinfo(host, port, socket.AF_INET,
                                   socket.SOCK_STREAM)[0][4]
 
@@ -230,12 +230,12 @@
 
         # All that hard work just to test if connect times out in 0.001s ;-)
         self.addr_remote = blackhole
-        with support.transient_internet(self.addr_remote[0]):
+        with socket_helper.transient_internet(self.addr_remote[0]):
             self._sock_operation(1, 0.001, 'connect', self.addr_remote)
 
     def testRecvTimeout(self):
         # Test recv() timeout
-        with support.transient_internet(self.addr_remote[0]):
+        with socket_helper.transient_internet(self.addr_remote[0]):
             self.sock.connect(self.addr_remote)
             self._sock_operation(1, 1.5, 'recv', 1024)