doc: remove erroneous comma in cluster explainer

PR-URL: #42238
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>

doc/api/cluster.md

@@ -98,7 +98,7 @@ handles back and forth.
 The cluster module supports two methods of distributing incoming
 connections.
 
-The first one (and the default one on all platforms except Windows),
+The first one (and the default one on all platforms except Windows)
 is the round-robin approach, where the primary process listens on a
 port, accepts new connections and distributes them across the workers
 in a round-robin fashion, with some built-in smarts to avoid