ENH: add lock parameter to Dataset.deposit

[neutrinoceros]

Follow up to #245: releasing the GIL and not having any sort of lock to replace it degrades performance in the general case, so it seems preferable to have some locking mechanism by default (while still allowing it to be disabled, as an opt-out)

TODO:

• evaluate the relative usefulness of supporting both per-instance and global, and choose a sane default if both should be conserved
• doc
• tests
  • add tests
  • check coverage. Requires TST: add Python 3.13 to normal CI #250