Add warning when loading plugins of type composer-installer as they are unlikely to function correctly and should be upgraded to the composer-plugin type
$this->io->writeError('<warning>Loading "'.$package->getName() . '" '.($isGlobalPlugin ? '(installed globally) ' : '').'which is a legacy composer-installer built for Composer 1.x, it is likely to cause issues as you are running Composer 2.x.</warning>');
$installer = new $class($this->io, $this->composer);
$installer = new $class($this->io, $this->composer);