PHILADELPHIA — Nico Batum greeted Tuesday’s post-shootaround media scrum with a “happy new year,” then downplayed the actual significance of the calendar flipping during the middle of the NBA season. “Nothing changes,” the 76ers’ veteran forward said. “It’s the same stuff as yesterday, or two days ago.” Still, 2024 is shaping up to be a critical year for the Sixers. They have a 23-10 record, good for third place in the Eastern Conference standings. They left the James Harden saga in 2023. They are moving into 2024 with a team anchored by reigning NBA Most Valuable Player Joel Embiid, rising st…