chore(deps): update dependency composer/composer to v2.8.8 (dockerfiles/dockerfile.renovate)

Author: IK Renovate Bot

dockerfiles/Dockerfile.renovate

@@ -116,7 +116,7 @@ RUN echo "deb http://ppa.launchpad.net/ondrej/php/ubuntu bionic main" > /etc/apt
     rm -rf /var/lib/apt/lists/*
 
 # renovate: datasource=github-releases depName=composer/composer
-ENV COMPOSER_VERSION=2.8.6
+ENV COMPOSER_VERSION=2.8.8
 
 RUN php -r "copy('https://github.com/composer/composer/releases/download/$COMPOSER_VERSION/composer.phar', '/usr/local/bin/composer');"