Occasional developer tasks

Update test_durations

See make durations, try to do on CI machines during a run (needs us to add a step)

Website build stalls after 60 days of inactivity

https://github.com/firedrakeproject/firedrakeproject.github.io

Check status of notebooks repo

https://github.com/firedrakeproject/notebooks

Add new backwards compat checkpoint files

• Run https://github.com/firedrakeproject/firedrake/blob/main/tests/firedrake/output/test_io_backward_compat.py directly (not through pytest)