DOC/BLD: update vendored IPython.sphinxext version
updated to commit cc353b25b0fff58e4ed13899df9b3c8153df01d9 from ipython/ipython

xref https://github.com/pandas-dev/pandas/issues/18147, https://github.com/pandas-dev/pandas/pull/19687

Alternative for https://github.com/pandas-dev/pandas/pull/19657 until new release of IPython is out