docs: Update requirements.txt

Fix readthedocs build issue.

ModuleNotFoundError: No module named 'sphinx.ext.mathbase'

Breathe dependency on sphinx.ext.mathbase

Signed-off-by: Ajay Bhargav <[email protected]>

Author: ajaybhargav

docs/requirements.txt

@@ -1,7 +1,7 @@
 # This is a list of python packages used to generate documentation. This file is used with pip:
 # pip install --user -r requirements.txt
 #
-sphinx>=1.8.4
-breathe==4.11.1
+Sphinx
+breathe==4.18.1
 sphinx-rtd-theme
 sphinx-notfound-page