The following changes will need to be made manually on the live python.org site prior to a release that includes iOS artefacts (hopefully 3.15.0b1):

• Under Downloads/Operating Systems, add an entry for iOS (slug iOS)
• Under Site Trees, add a Downloads menu item for iOS (path downloads/ios)
• Under Boxes/Boxes, add a link for <a href="/downloads/ios/">iOS</a> to the download-banner.

This PR adds fixtures that reflect the same changes, so that developers have a site that reflects what the live site will have.

The fixtures cheat a little bit, piggybacking off the fixtures added to support Android releases. There are no 3.14 releases for iOS; but the purpose of the fixtures is to demonstrate that rendering of the download page works, rather than being a canonical data source.

Refs python/cpython#140189