add redis service in drone

.drone.yml

@@ -38,7 +38,7 @@ steps:
     - name: phpunit_tests
       image: php:8.1.6
       commands:
-          - apt-get update && apt-get install -y redis-server libcurl3-dev apt-utils zlib1g-dev libpng-dev libicu-dev libonig-dev rsync texlive-base texlive-xetex texlive-lang-german texlive-fonts-extra
+          - apt-get update && apt-get install -y libcurl3-dev apt-utils zlib1g-dev libpng-dev libicu-dev libonig-dev rsync texlive-base texlive-xetex texlive-lang-german texlive-fonts-extra
           - docker-php-ext-install pdo_mysql curl gd intl mbstring
           - pecl install redis && docker-php-ext-enable redis
           - cp .docker/fonts/* /usr/share/fonts/
@@ -56,6 +56,7 @@ steps:
           LOG_CHANNEL: stack
           DB_CONNECTION: mysql
           DB_HOST: db
+          REDIS_HOST: redis
           DB_PORT: 3306
           DB_DATABASE: db
           DB_USERNAME: db
@@ -140,6 +141,8 @@ services:
           MARIADB_USER: db
           MARIADB_PASSWORD: db
           MARIADB_ALLOW_EMPTY_PASSWORD: yes
+    - name: redis
+      image: redis
 
 trigger:
     event: