Bug#1084781: pydata-sphinx-theme missing templates etc

[Rebecca N. Palmer]

That's not enough: it now can't find static/webpack-macros.html , which 
doesn't exist as a file in the source.

https://salsa.debian.org/rnpalmer-guest/pydata-sphinx-theme/-/jobs/6398738
It looks like this file is supposed to be created by 
sphinx-theme-builder, but that our patch might be disabling that and/or 
our version of it might be too old.