Update composer Docker tag to v2.8.4

Author: renovate[bot]

Dockerfile

@@ -2,7 +2,7 @@ FROM php:8.3.13-alpine
 
 ENV COMPOSER_HOME="/tmp/composer"
 
-COPY --from=composer:2.8.3 /usr/bin/composer /usr/bin/composer
+COPY --from=composer:2.8.4 /usr/bin/composer /usr/bin/composer
 
 RUN set -x \
     && apk add --no-cache git \