when the iphone 11 will be obsolet

Apple discontinued the iPhone 11 in September 2022.

See the following from Obtaining service for your Apple product after an expired warranty - Apple Support

Products are considered obsolete when Apple stopped distributing them for sale more than 7 years ago.

Apple stopped distributing the iPhone 11 in 2022. So it should be beyond 2025 before this becomes a vintage product.

Obtaining service for your Apple product after an expired warranty - Apple Support

will the iPhone 11 be obsolete in 2025

No

http://consultants.apple.com/