PYTHON-1975 Bump max wire version to 9 (MongoDB 4.4)

Author: prashantmital

pymongo/common.py

@@ -58,7 +58,7 @@
 # What this version of PyMongo supports.
 MIN_SUPPORTED_SERVER_VERSION = "2.6"
 MIN_SUPPORTED_WIRE_VERSION = 2
-MAX_SUPPORTED_WIRE_VERSION = 8
+MAX_SUPPORTED_WIRE_VERSION = 9
 
 # Frequency to call ismaster on servers, in seconds.
 HEARTBEAT_FREQUENCY = 10