fix: wait for threads to be exited on closing workers (#444)

Author: supercaracal

lib/redis_client/cluster/concurrent_worker/pooled.rb

@@ -37,7 +37,9 @@ def push(task)
 
         def close
           @q.clear
-          @workers.each { |t| t&.exit }
+          workers = @workers.compact
+          workers.each(&:exit)
+          workers.each(&:join)
           @workers.clear
           @q.close
           @pid = nil

lib/redis_client/cluster/pub_sub.rb

@@ -26,7 +26,11 @@ def ensure_worker
         end
 
         def close
-          @worker.exit if @worker&.alive?
+          if @worker&.alive?
+            @worker.exit
+            @worker.join
+          end
+
           @client.close
         rescue ::RedisClient::ConnectionError
           # ignore