Break them up, one way or another
The major problem in a TTRPG with a single character who does "everything" is that there is no reason for the events of the plot to revolve around that single character. It's exciting in a novel where one character is the protagonist, and most plot events may be expected to happen to (or at least around) that character, for that character to have the skills, knowledge, and motivation to address those events. A TTRPG, in contrast, has as many protagonists as it has players. This is a major tool for the GM to use.
For as much as this player wants their PC to be capable of handling anything that might come up, the world doesn't revolve around their character. Plot events are meant to be things that the PC party can deal with, not just one character. So in the worst case, if this player really can trivialize most non-combat encounters, the most direct solution is to have more things than one person can handle be relevant to the party's goals. That might be a two-step plan, where both steps need to be carried out simultaneously, or forcing the party to separate so that the min-maxed PC can't solve everyone's problems. It's not a permanent solution, but this PC being able to address any problem in front of them doesn't help with problems that aren't in front of them.
Circumvent the min-maxer's preparations
Not my favorite solution, but it can be appropriate in specific cases. That the PC's stats are so heavily optimized is a double-edge sword: you, as GM, know what challenges this character can deal with and which ones they would struggle with. You are not obligated to present the player exclusively with obstacles their character is best equipped to deal with. Gating certain events, items, etc., behind challenges which this PC is not well suited to handle negates their advantages. You can design obstacles which this PC is expected to fail.
That's annoying for a player when their character has specialized in some particular task or other, because they can feel cheated by having invested in a particular strategy to (arbitrarily) no benefit. But when a player has designed their character to make huge swathes of the game irrelevant the formula changes a bit. I wouldn't override this PC's focus all the time, but making it clear that the PC can't just automatically win all the time is both appropriate and ensures that the "game" elements of the game remain.
My favorite tactic for this kind of thing (which may or may not fit your game well) is to find a way to attach a reputation to the overpowered PC. If they gain a sinister reputation and no one in town will willingly deal with them, then all the skill ratings in the world won't help much. I've had good results with this strategy when there is a location players will find themselves in often (like a central hub city) where the min-maxed player can be pretty sure they won't be able to run roughshod over your challenges. That way min-maxing is still useful, especially in side-quests and the like, but it doesn't make the "central" plot irrelevant. Meanwhile, all other players can use their characters' skills in the normal way; it's only the min-maxer's extreme bonuses that are affected.
If this becomes irritating for the player of the min-maxed PC, you can offer to let them re-spec their character such that they don't need this type of nerfing, roll another character, or something similar.
Retire this character
TTRPGs typically rely on PCs being similarly powerful, and not on a single PC dealing with most challenges. If this character is optimized to the point that the other characters in the party are redundant, then it's not a character suited to this campaign. In the interest of maintaining the fun of the game for everyone, you're well within your GM rights to ask the player to roll a different character so that the game can be fun for everyone (not just that player).
This route requires that you speak with the other players to make sure that the min-maxed PC is damaging their fun. If it isn't, then there isn't a problem to solve (with regard to the other players' feeling overshadowed) and any issue that exists is more likely to lie with your approach encounter design than this character, specifically. But if the optimization makes it impossible for all of these PCs to participate in the same game at the same time, that's what you'll need to address.
Remember who the GM is
This player is using the rules (presumably fairly) to dictate how the game will play out: challenges will come up, and their PC will easily overcome them. That's not how TTRPGs work. The point of having a GM is to manage the game in ways that offer challenging, but achievable, objectives. There is no combination of rules and game features which contravene this-- there is no Konami Code to make the game so easy, and someone who wants to automatically succeed (or close enough as makes no difference) doesn't need to use hours of others' time to do it. They can sit with a set of Pathfinder books and say "I win" as often as they please.
You are more than free to design obstacles which frustrate or obviate the min-maxed character, not as a punishment, but as things which meaningfully challenge so accomplished a PC. If this is a problem for the other PCs (for example, because they can't realistically survive such challenges), you can try to segment obstacles so that the "hard" ones face the min-maxed character and the others face the rest of the players. If this unbalances the game, you can point back to the unbalancing factor as the root problem and try one of the other strategies offered under this question.
Addressing this over-tuned PC is no more an abuse of the game rules than over-tuning the PC in the first place. This PC doesn't get to declare that all obstacles are, effectively, already overcome. You are in charge of the in-game universe, and so if the universe needs to act to remedy this disparity, it can.