Bump Python requirement mkdocs to 1.4.2

docs-requirements.txt

 black==22.10.0
 doc8==1.0.0
-mkdocs==1.4.1
+mkdocs==1.4.2
 mkdocs-material==8.5.8
 mkdocstrings==0.19.0
 mkdocstrings-python==0.7.1