SPRINGFIELD — When lawmakers return to the Capitol next week for their annual fall veto session, they have a full agenda, including a handful of vetoes from Gov. J.B. Pritzker to consider overriding, in addition to deciding whether to revive a private school scholarship program.But additional state spending is unlikely to be on their agenda, according to recent comments from both the governor and House Speaker Emanuel “Chris” Welch.The prospect of a supplemental spending plan had been floated in recent …