Log Message:
py-time-machine: updated to 2.13.0

2.13.0 (2023-09-19)
-------------------
* Add support for ``datetime.timedelta`` to ``time_machine.travel()``.
* Fix documentation about using local time for naive date(time) strings.
* Add ``shift()`` method to the ``time_machine`` pytest fixture.
* Mock ``time.monotonic()`` and ``time.monotonic_ns()``.
  They return the values of ``time.time()`` and ``time.time_ns()`` respectively, \ 
rather than real monotonic clocks.