This is the perfect time to practice setting boundaries. Go to office on time, leave on time. Provide conservative estimates for tasks, don't stretch your work hours. If tasks are not well defined, ask a lot of clarifying questions. If your manager overrides your estimates for deliverables and tasks are delayed, say I told you so during retro meetings.
If tasks were not being planned properly earlier, you asking for more information will just cause the manager to give it to some other poor sod. Not your problem.
If the manager implies that you are not meeting expectations, shrug and move on. You're a notice period bitch. Not your problem.
Don't burn yourself out during notice period. Do your job, but at a sedate pace. You will have a learning curve in the new role, you're settling yourself up for failure if you jump ship burnt out.