[build] remove the flag --ignore-platform-reqs for Composer
[build] remove the flag --ignore-platform-reqs for Composer

Composer should follow requirements about the PHP version indicated into the composer.json file.

3liz/lizmap-web-client,3liz/lizmap-web-client,3liz/lizmap-web-client,laurentj/lizmap-web-client,rldhont/lizmap-web-client,laurentj/lizmap-web-client,laurentj/lizmap-web-client,3liz/lizmap-web-client,rldhont/lizmap-web-client,laurentj/lizmap-web-client,rldhont/lizmap-web-client,rldhont/lizmap-web-client