With newer sphinx the pdf build fails and gives the following error:
! Dimension too large.
This could be memory issue, that can be fixed by not generating the
sample_policy file as that can be large.
This patch also sets back the tox-docs job as voting.
Closes-Bug: #1918707
Change-Id: I4f22fe7b45394045f672d5bbd3b46c4e5e4b2fd3
4bfea794d7