Is there anything in Magic that can turn a token permanent into a nontoken permanent?
Within the actual rules definition for "Token", such a thing really isn't possible.
111.1. Some effects put tokens onto the battlefield. A token is a marker used to represent any permanent that isn't represented by a card.
With this definition, something becoming a nontoken really means that the thing becomes a card. And to become a card, you need a physical real-world card to have a card in general.
So as long as something is a permanent, and it isn't represented by a card, then it is a token. The closest thing you could do is replace a token with a different non-token that does the same thing... i.e. you could have an ability that says "sacrifice target Forest token. Choose a Forest card you own from outside the game and put it on the battlefield."
But if an ability said something like "target token becomes a non-token", it would just be confusing... Even though effects on cards can override any rules in the rulebook; an effect like this would basically be just redefining the word "token" as it is in the rules. Assuming that you aren't talking about it actually becoming a card; then it becomes an entirely new thing that is a concept never thought of in the rules... a permanent that is neither a token nor a card. You would need to alter a ton of other rules to make it work... what happens when this non-token, non-card enters a graveyard? You would likely need to replace the rules that make tokens in graveyards cease to exist with a rule that applies to all non-cards in graveyards instead.
GendoIkari's answer is technically correct... A token by definition is not a card, but misses one new corner case to have emerged from Ikoria: Mutate
Mutate can take a card (non-token) and combine it with an existing permanent (non-human creatures only, but tokens are a valid target) to modify the existing permanent, using one of the two as the template... You can therefore have a creature card be technically a token (The token's stats are used as the 'top' or default state) or have a token become a non-token (the mutate card goes on top and changes the default state), the second of which results in a permanent that has changed from being a token to not being token.
But honestly, most people just use a card like Skullclamp or Foster to get non-token cards from a token :-p