fix(docker): build without gitignored composer lock files

Dockerfile

@@ -2,8 +2,8 @@
 
 FROM composer:2 AS vendor
 WORKDIR /app
-COPY composer.json composer.lock symfony.lock ./
-RUN composer install --no-dev --no-scripts --prefer-dist --no-interaction --ignore-platform-reqs
+COPY composer.json ./
+RUN composer update --no-dev --no-scripts --prefer-dist --no-interaction --ignore-platform-reqs
 COPY . .
 RUN composer dump-autoload --classmap-authoritative --no-dev \
     && composer run-script --no-dev post-install-cmd || true