PYTHON-3452 Skip SDAM test that relies on retryWrites on MMAPv1 (#1071)

Author: ShaneHarvey

test/unified_format.py

@@ -936,6 +936,7 @@ def maybe_skip_test(self, spec):
             if (
                 "Dirty explicit session is discarded" in spec["description"]
                 or "Dirty implicit session is discarded" in spec["description"]
+                or "Cancel server check" in spec["description"]
             ):
                 self.skipTest("MMAPv1 does not support retryWrites=True")
         if "Client side error in command starting transaction" in spec["description"]: