That is contradicted by publication 334, page 36, that has a CAUTION icon and says:
Do not deduct state and local sales taxes im-
posed on the buyer that you must collect and pay
over to the state or local government. Do not in-
clude these taxes in gross receipts or sales.
https://www.irs.gov/pub/irs-pdf/p334.pdf
I guess the difference is "imposed on the buyer" vs "imposed on you as the seller" State sales taxes in the U.S. are generally imposed on the buyer not the seller. So the advice in pub 334 applies for most cases of state sales tax. The note that you linked sounds like it applies to other types of sales taxes that are imposed on the seller of a good (off the top of my head, I think perhaps a seller of gasoline where a sales/excise tax is built into the price might be an example of this).
