[Docs] Pin pydata-sphinx-theme to 0.8 to avoid dark mode

[asfimport]

pydata-sphinx-theme introduced automatic dark mode. However there is a series of changes we need to do (such as providing a dark-mode Arrow logo) before we will be ready for this (see ARROW-17152). For the 9.0.0 release, we should instead pin to the version of pydata-sphinx-theme just before that release.

Reporter: Will Jones / @wjones127
Assignee: Will Jones / @wjones127

Related issues:

• [Python][Docs] Enable building documentation with pyarrow nightly builds (relates to)
• [Docs] Enable dark mode on documentation site (is related to)

PRs and other links:

• GitHub Pull Request #13663

_{Note: This issue was originally created as ARROW-17151. Please see the migration documentation for further details.}

[asfimport]

Kouhei Sutou / @kou:
Issue resolved by pull request 13663
#13663