py-ipython: updated to 7.6.0

IPython 7.6.0

IPython 7.6.0 contains a couple of bug fixes and number of small features additions as well as some compatibility with the current development version of Python 3.8.

Add a -l option to %psearch to list the available search types.
Support PathLike for DisplayObject and Image.
Configurability of timeout in the test suite for slow platforms.
Accept any casing for matplotlib backend.
Properly skip test that requires numpy to be installed
More support for Python 3.8 and positional only arguments (pep570)
Unicode names for the completion are loaded lazily on first use which should decrease startup time.
Autoreload now update the types of reloaded objects; this for example allow pickling of reloaded objects.
Fix a big where %%time magic would suppress cell output.

(adam)