iOS 16 supports AVIF and WebP

[n0vad3v]

From https://caniuse.com/avif we know that starting from iOS 16, it supports AVIF, but browser on iOS will not send the correct Accept header, on a testing machine (iPhone 11 + iOS 16.6 + Chrome), requests headers are:

• UA: Mozilla/5.0 (iPhone; CPU iPhone OS 16_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/114.0.5735.124 Mobile/15E148 Safari/604.1
• Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

While on Chrome on Linux, UA and accept are:

• UA: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36
• Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7

In cases above, if we found iPhone OS 16 in UA, we should be able to render WebP/AVIF to them, without checking their Accept header.

[github-actions[bot]]

ghcr.io/webp-sh/webp_server_go (debian 12.0)
============================================
Total: 0 (HIGH: 0, CRITICAL: 0)

[github-actions[bot]]

ghcr.io/webp-sh/webp_server_go (debian 12.0)
============================================
Total: 0 (HIGH: 0, CRITICAL: 0)

[github-actions[bot]]

ghcr.io/webp-sh/webp_server_go (debian 12.0)
============================================
Total: 0 (HIGH: 0, CRITICAL: 0)