Hello!

I tried to install many extensions with composer, but a few times I ran into a few issues, this one is about the requirement of composer v1.

Many other extensions depend on composer v2, so installing them together is not possible.

This can be changed like in this commit in a fork of mine: https://github.com/markus-96/mediawiki-extensions-Variables/commit/0db7ce6e7032f1e1f05bbb555a8f2acad45fe744

Or like this: https://gerrit.wikimedia.org/r/c/mediawiki/extensions/PageForms/+/942478/
That resolves the same issue in the PageForms extension: T340818