Pinning ipython version to be less than 8.13.

Starting with ipython version 8.13.0, ipython will not support Python
versions less than 3.9 and we still support 3.8, so pinning.

Prints out the following:

ImportError:
IPython 8.13+ supports Python 3.9 and above, following NEP 29.
IPython 8.0-8.12 supports Python 3.8 and above, following NEP 29.
When using Python 2.7, please install IPython 5.x LTS Long Term Support version.
Python 3.3 and 3.4 were supported up to IPython 6.x.
Python 3.5 was supported with IPython 7.0 to 7.9.
Python 3.6 was supported with IPython up to 7.16.
Python 3.7 was still supported with the 7.x branch.

Author: zivy

requirements_dev.txt

@@ -3,5 +3,5 @@ pytest
 markdown
 lxml
 pyenchant
-ipython
+ipython<=8.12
 -rPython/requirements.txt