Support Composer 2.x

[jamesmontalvo3]

Per #1272, Composer 2.x broke Meza. Meza will be made to enforce Composer 1.x install. However, long term we should figure out how to support Composer 2.x

[djflux]

Finally got the 35.x branch from here ported over to run successfully on Rocky Linux 8.6. Uses composer 2.1.14. Anything newer requires updates to mediawiki/composer.json due to allow-plugins security changes with Composer 2.2.0+

https://getcomposer.org/doc/06-config.md#allow-plugins

Will check with you on Tuesday 31 May 2022 about a pull request from my repo to the 35.x branch here.

If you want to check my repo out the commit that works is:

https://github.com/djflux/meza/tree/336c3c985631e229cd9d51ccdde54535c953c0eb