Section update: Single sign-on 4.3

[Arcapas]

Description

This PR aims to update the section Single sign-on.

Checks

• Compiles without warnings.
• Uses present tense, active voice, and semi-formal registry.
• Uses short, simple sentences.
• Uses bold for user interface elements, italics for key terms or emphasis, and code font for Bash commands, file names, REST paths, and code.
• Uses three spaces indentation.
• Adds or updates meta descriptions accordingly.
• Updates the redirects.js script if necessary (check this guide).