Remove outdated Edge version and update the UA detection article

[captainbrosset]

Fixes #3000 and updates the UA detection article.

• Before: https://learn.microsoft.com/en-us/microsoft-edge/web-platform/user-agent-guidance
• After: https://review.learn.microsoft.com/en-us/microsoft-edge/web-platform/user-agent-guidance?branch=pr-en-us-3003

AB#48368626

[learn-build-service-prod[bot]]

Learn Build status updates of commit 15814a7:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/web-platform/user-agent-guidance.md	:white_check_mark:Succeeded	View

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