gh-127313: Use getLogger() without argument to get root logger in logging cookbook (GH-143683)

Use getLogger() to get root logger in logging cookbook
(cherry picked from commit 53fecbe6e116a4426058b7d0f6c451719c72cb5b)

Co-authored-by: AN Long <aisk@users.noreply.github.com>

Author: aisk

Doc/howto/logging-cookbook.rst

@@ -229,7 +229,7 @@ messages should not. Here's how you can achieve this::
    # tell the handler to use this format
    console.setFormatter(formatter)
    # add the handler to the root logger
-   logging.getLogger('').addHandler(console)
+   logging.getLogger().addHandler(console)
 
    # Now, we can log to the root logger, or any other logger. First the root...
    logging.info('Jackdaws love my big sphinx of quartz.')
@@ -650,7 +650,7 @@ the receiving end. A simple way of doing this is attaching a
 
    import logging, logging.handlers
 
-   rootLogger = logging.getLogger('')
+   rootLogger = logging.getLogger()
    rootLogger.setLevel(logging.DEBUG)
    socketHandler = logging.handlers.SocketHandler('localhost',
                        logging.handlers.DEFAULT_TCP_LOGGING_PORT)