Add default functional cache support with PHP Memcached extension

[mabed-fr]

Hello

The official PrestaShop Docker image currently does not include the PHP Memcached extension.
Memcached is a widely used caching backend that can significantly improve performance by reducing database queries and speeding up page loads.

Including this extension by default would allow store owners to enable object caching in PrestaShop without rebuilding the Docker image.

Use cases :

Enable object caching with Memcached directly in PrestaShop.

Improve performance for high-traffic stores.

Simplify deployment in containerized environments.

Regards