Ensure that all dist bots contain build the same set of docs

[brson]

As mentioned in #16456, pandoc/latex are not pervasive and are probably not available on our mac/win builders. We're going to start installing docs and should distribute a consistent set with every platform.

I would not mind solving this by just disabling PDF's from the dist set.

[steveklabnik]

We have disabled PDF docs, so this isn't an issue anymore.