Exclude "viewport" meta tag audit for desktop devices

[istayev]

Feature request summary
We request that Lighthouse stop auditing the "viewport" meta tag on desktop devices, as it is only relevant for mobile devices. More details: Lighthouse Best Practices - Viewport.

What is the motivation or use case for changing this?
We aim to improve our SEO Lighthouse score and believe that ignoring this audit for desktop devices would provide more accurate results.

How is this beneficial to Lighthouse?
This change would ensure Lighthouse properly audits the "viewport" meta tag only where it is applicable, leading to more relevant recommendations.