Remove duplicate devguide link from footer

[hugovk]

Description

• We have two Developer's Guide links in the footer, the other under Docs, one under Contributing
• The Contributing one makes more sense
• This PR removes is from the test fixtures
• Please can someone with access remove it from the site tree in the CMS? I don't have access. The link is https://www.python.org/admin/sitetree/tree/1/change/

Closes

• Fixes Enhancement: Improve Visibility and Naming Consistency of "Developer's Guide" on the Main Website Navigation #2727

[JacobCoffee]

i'll grab the cms fix when i get back to my laptop