Extend the ignored part of IPython outputs

[frenzymadness]

With IPython 8.1, there is again a difference in tracebacks which causes three tests of nbclient to fail like this:

E             Full diff:
E               [
E                {'ename': 'KeyboardInterrupt',
E                 'evalue': '',
E                 'output_type': 'error',
E                 'traceback': ['---------------------------------------------------------------------------',
E                               'KeyboardInterrupt                         Traceback (most '
E                               'recent call last)',
E             -                 '<IPY-INPUT> in <cell line: 1>()\n'
E             ?                                  ^ ---------- --
E             +                 '<IPY-INPUT> in <module>\n'
E             ?                                  ^^^^^
E                               '----> 1 while True: continue\n',
E                               'KeyboardInterrupt: ']},
E               ]

nbclient/tests/test_client.py:231: AssertionError
…
=========================== short test summary info ============================
FAILED nbclient/tests/test_client.py::test_run_all_notebooks[Interrupt.ipynb-opts6]
FAILED nbclient/tests/test_client.py::test_run_all_notebooks[Skip Exceptions with Cell Tags.ipynb-opts8]
FAILED nbclient/tests/test_client.py::test_run_all_notebooks[Skip Exceptions.ipynb-opts9]
============ 3 failed, 73 passed, 106 warnings in 65.37s (0:01:05) =============

It seems to me that it's good idea to extend the ignored part of IPython input so I've prepared the regexes for that.

[davidbrochart]

Thanks @frenzymadness, the CI failures are unrelated.