You are playing with words!
First, you need to provide your omniscient being! ?Does such a thing exist?
Then you need to check on your definitions of both knowledge and intelligence, and is it possible for new knowledge to come into existence?
Next up you need to prove your assertion that "all intelligent beings can learn". It's probably a "Black Swan fallacy"!
Sorry, but if you break down your statement it's just wrong from start to finish! If you are trying to use this to disprove god, any god, even if the statement were true, it still doesn't disprove god(s)!