Can't detect iOS version when requesting desktop site by Chrome

[masato-hi]

Description

When requesting a desktop site with this MR, it is now detect to be iOS.
#548

However, the version of iOS cannot be detected from the user agent.

How to reproduce

irb(main):034> Browser.new('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/130 Version/11.1.1 Safari/605.1.15').platform.ios?
=> true
irb(main):035> Browser.new('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/130 Version/11.1.1 Safari/605.1.15').platform.version
=> "0"

What do you expect

Add a method to detect iOS desktop site requests.

At the same time, it might be better to revert this MR.