I said zero because you framed the time as between now and the election, with a hypothetical removal of Biden (which I think is very likely, yes). In this frame, I'm quite confident with "zero".
You don't just wake up one morning in Beijing and say, ok today we invade Taiwan because the old boy is out. It just doesn't work like that. It's not physically or logistically possible. Hence, zero probability.
Even bombing and destroying TSCM is not something you just "do". It would require full war preparations that take a lot longer than the time you've given. Because even if Xi used covert or black ops, everybody would know it had been him and the consequences would be immediate.
If you said in 5 years, I would give an extremely low but non-zero probability. And as we go further into the future and start to introduce unknowns like a hypothetical successor for Xi, or any other number of things, the odds may increase.
Specifically, I think the most important factor is the US developing its own SC capabilities at home. THAT would increase the odds of an attack or even an invasion drastically, but still long term.