`deploy-ftp.py` requires Python 3.11 but this is not noted anywhere

[OatmealDome]

deploy-ftp.py now requires Python 3.11 with the merging of #9. (config.mk states Python 3.4+ is required, but this wasn't updated.)

[mariopossamato]

Unfortunately, I forgot to change that in my PR, lol! Also, it might be worth mentioning that ftputil is required as well. Sorry about that! 😅