Un-remove deprecated "style" field from html_context

[mgeier]

Purpose

The style field was removed in #11381, obsoleted by styles.

However, this broke many old themes.

To be concrete, on https://sphinx-themes.org/ there are currently 10 themes that are broken by this.

Relates

• #11931

[AA-Turner]

This went through the standard deprecation policy, I am hesitant to reverse it all simply as old themes are no longer maintained.

Juan-Luis makes a good point in https://github.com/sphinx-doc/sphinx/issues/11931#issuecomment-1926905417:

Sphinx breaking themes that haven't been touched in 5+ years is hardly Sphinx['s] fault

On the linked issue, for example, I haven't seen efforts from those themes to update. We have a fairly conservative compatability policy, which has been advertised for many years now.

The unaffiliated sphinx-themes.org website could consider changing their visual presentation of the failing themes such that all of them are positioned at the end, or hidden by default, which would make the experience less jarring.

A

[AA-Turner]

No dissent for a couple of months; closing.

A