py-mongo: updated to 4.5.0

Changes in Version 4.5
----------------------

PyMongo 4.5 brings a number of improvements including:

- Added new helper methods for Atlas Search Index (requires MongoDB Server 7.0+):
  :meth:`~pymongo.collection.Collection.list_search_indexes`,
  :meth:`~pymongo.collection.Collection.create_search_index`,
  :meth:`~pymongo.collection.Collection.create_search_indexes`,
  :meth:`~pymongo.collection.Collection.drop_search_index`,
  :meth:`~pymongo.collection.Collection.update_search_index`
- Added :meth:`~pymongo.database.Database.cursor_command`
  and :meth:`~pymongo.command_cursor.CommandCursor.try_next` to support
  executing an arbitrary command that returns a cursor.
- ``cryptography`` 2.5 or later is now required for :ref:`OCSP` support.
- Improved bson encoding and decoding performance by up to 134%(`PYTHON-3729`_, `PYTHON-3797`_, `PYTHON-3816`_, `PYTHON-3817`_, `PYTHON-3820`_, `PYTHON-3824`_, and `PYTHON-3846`_).

.. warning:: PyMongo no longer supports PyPy3 versions older than 3.8. Users
  must upgrade to PyPy3.8+.

(adam)