Add PHPStan installers to base setup

magento-phpstan/entrypoint.sh

@@ -10,7 +10,7 @@ if [ -z "$COMPOSER_VERSION" ] ; then
 fi
 
 MAGENTO_ROOT=/var/www/magento2ce
-test -d "${MAGENTO_ROOT}" || (test -d /var/www/magento2ce && MAGENTO_ROOT=/m2)
+test -d "${MAGENTO_ROOT}" || (test -d /var/www/magento2ce && MAGENTO_ROOT=/tmp/m2)
 
 test -z "${COMPOSER_NAME}" && (echo "'composer_name' is not set in your GitHub Actions YAML file" && exit 1)
 
@@ -20,6 +20,9 @@ ln -s /usr/local/bin/composer$COMPOSER_VERSION /usr/local/bin/composer
 echo "Fix issue 115"
 cd $MAGENTO_ROOT
 rm -rf vendor/
+composer config allow-plugins.phpstan/extension-installer true
+composer require --dev phpstan/extension-installer --no-update
+composer require --dev bitexpert/phpstan-magento --no-update
 composer install
 
 echo "Setup extension source folder within Magento root"