In classic Jira projects we are able to remove non-working days from a Sprint to help more accurately plan velocity. I've looked at the documentation for Next-Gen projects and this doesn't seem to be present. Am I missing it, or is this not implemented yet?
Currently, next-gen project does not have "Board settings", so it's not possible to configure the Working days.
Based on your question, I've created a feature request:
Please, click on vote and watch to receive updates about the feature.
Of course we can expect more and more features to be added, after losing some coming from classic. *face palm* sorry. That is just a very weak reply to respond to feature loss... especially for such elemental aspects like working days, where without this feature, burndown charts just become useless. And noone noticed that during rewriting from scratch? Again, sorry for my frank words, but that is a weak statement.
Actually, I think that JSWCLOUD-17666 better represents the original poster's request. The other "board settings" features from classic Jira are nice, but without non-working days, the burn-up report misrepresents the data presented.