update composer plugin api version

[mauriau]

Composer just merged the branch 2.0 into master. https://github.com/composer/composer/commit/87757de6bcf42b1833faba963d4f24bb2fb3ef22

So we got this issue : - hirak/prestissimo 0.3.10 requires composer-plugin-api ^1.0.0 -> found composer-plugin-api[2.0.0] but it does not match your constraint.

[baukevdw]

For more information see: https://github.com/composer/composer/issues/8726

[Seldaek]

For prestissimo, as composer 2 comes with parallel downloads built-in, it probably makes more sense to not support v2, or to support it but to disable prestissimo completely if composer version is 2.