Is your feature request related to a problem? Please describe.
Upgrade default PHP engine from 8.3 to 8.4

As it now available on Alpine Linux Packages : see https://pkgs.alpinelinux.org/packages?name=php84&branch=edge&repo=&arch=x86_64&origin=&flagged=&maintainer=

Describe the solution you'd like
Upgrade https://github.com/oxsecurity/megalinter/blob/main/megalinter/descriptors/php.megalinter-descriptor.yml

I can suggest a PR

Describe alternatives you've considered
No alternative exists, except if we keep on PHP 8.3