fix plugin allow (#55)

Author: garak

Dockerfile

@@ -9,7 +9,7 @@ LABEL "repository"="http://github.com/oskarstark/phpstan-ga"
 LABEL "homepage"="http://github.com/actions"
 LABEL "maintainer"="Oskar Stark <oskarstark@googlemail.com>"
 
-COPY --from=composer:2.2.4 /usr/bin/composer /usr/local/bin/composer
+COPY --from=composer:2.3.10 /usr/bin/composer /usr/local/bin/composer
 
 RUN mkdir /composer
 ENV COMPOSER_HOME=/composer
@@ -19,6 +19,7 @@ RUN echo "memory_limit=-1" > $PHP_INI_DIR/conf.d/memory-limit.ini
 ENV VERSION=1.8.2
 
 RUN composer global require phpstan/phpstan $VERSION \
+    && composer global config --no-plugins allow-plugins.phpstan/extension-installer true \
     && composer global require phpstan/extension-installer \
     && composer global require phpstan/phpstan-doctrine \
     && composer global require phpstan/phpstan-phpunit \