refactor(docker): remove unused PHP extensions from Dockerfile to streamline image size

Dockerfile

@@ -13,14 +13,9 @@ RUN apt-get -o Acquire::Check-Valid-Until=false update \
         unzip \
     && install-php-extensions \
         bcmath \
-        dom \
         intl \
-        mbstring \
-        opcache \
         pcntl \
         pdo_mysql \
-        xml \
-        xmlreader \
         zip \
     && curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer \
     && apt-get purge -y --auto-remove \