Update docker/php-fpm/Dockerfile

docker/php-fpm/Dockerfile

 FROM gitlab-registry.in2p3.fr/cc-in2p3-devops/openshift-origin/openshift-images/php-fpm:stable-alpine
 LABEL maintainer="CNRS/CCIN2P3 DevOps Team"
 
-RUN apk update \
-    && apk add zlib-dev libpng-dev libjpeg-turbo-dev freetype-dev \
+RUN apk add --no-cache --virtual .php-build zlib-dev libpng-dev libjpeg-turbo-dev freetype-dev \
     && docker-php-ext-configure gd --with-freetype --with-jpeg \
     && docker-php-ext-install -j$(nproc) gd
 
-RUN apk add composer yarn npm
-
 ADD tms /var/www/html/
 WORKDIR /var/www/html
 
-RUN mv .env.template .env
-RUN php composer.phar install
-RUN yarn install --ignore-engines
-RUN yarn encore dev
+RUN apk add --no-cache --virtual .php-tools composer yarn npm \
+    && mv .env.template .env \
+    && php composer.phar install \
+    && yarn install --ignore-engines \
+    && RUN yarn encore dev \
+    && apk del .php-tools