Symfony version(s) affected: 5.1.5
Description
With Windows 8 and PHP 7.4, an exception is thrown:
Here the phpinfo if needed : https://gist.github.com/Surfoo/293c14052c882c08bfab1368af38a3e7
Exception "Symfony\Component\String\UnicodeString" requires a translit-able iconv implementation, try installing "gnu-libiconv" if you're using Alpine Linux.

How to reproduce
In a controller :
dd((string) $this->slugger->slug('🐎 test unicode character'));