One time charges are pretty typical when layoffs are announced. They are usually the cost of severance pay for the weeks or months of salary paid to employees who are no longer working. Office space leases are typically long term (multiple years) and accounting rules require they recognize the expected future cost of that now-useless space when the layoff decision is made. In practice, cash won't actually change hands for the office space until rent is due in future months. And companies will work with the landlord to get out of the lease (but often pay some penalty for the privilege).
I’d guess some of that is accounting for taxes on profit they’ll now have to pay that otherwise would have been deductible if spent on salaries for R&D?
Also, please note that maybe not all employees on this layoff are US-based.
In several countries, laying off people come with legal requirements for mandatory minimal severance, health insurance extensions, legal taxes and government fees and all kind of compensatory one-time payments for the fired employeer.
Possibly a bad LLM edit; maybe they meant to say would save $230 million through reduced headcount and less office space?