fix(transactions): fix error message for attempting sharded

transactions below 4.2

The original error would throw for all sharded deployments.
This fixes the wire check and makes sure it only throws
for wire checks below wire version 8

lib/core/sessions.js

@@ -192,8 +192,8 @@ class ClientSession extends EventEmitter {
     const topologyMaxWireVersion = maxWireVersion(this.topology);
     if (
       isSharded(this.topology) &&
-      (topologyMaxWireVersion == null ||
-        topologyMaxWireVersion < minWireVersionForShardedTransactions)
+      topologyMaxWireVersion != null &&
+      topologyMaxWireVersion < minWireVersionForShardedTransactions
     ) {
       throw new MongoError('Transactions are not supported on sharded clusters in MongoDB < 4.2.');
     }

lib/core/utils.js

@@ -87,6 +87,13 @@ function maxWireVersion(topologyOrServer) {
     return topologyOrServer.ismaster.maxWireVersion;
   }
 
+  if (typeof topologyOrServer.lastIsMaster === 'function') {
+    const lastIsMaster = topologyOrServer.lastIsMaster();
+    if (lastIsMaster) {
+      return lastIsMaster.maxWireVersion;
+    }
+  }
+
   if (topologyOrServer.description) {
     return topologyOrServer.description.maxWireVersion;
   }