chore(docker): replace Composer installation command with a pre-packaged composer.phar for improved build efficiency

Dockerfile

@@ -16,13 +16,15 @@ RUN apt-get -o Acquire::Check-Valid-Until=false update \
         libzip-dev \
         unzip \
     && docker-php-ext-install -j"$(nproc)" bcmath intl pcntl pdo_mysql zip \
-    && curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer \
     && apt-get purge -y --auto-remove \
         default-libmysqlclient-dev \
         libicu-dev \
         libzip-dev \
     && rm -rf /var/lib/apt/lists/*
 
+COPY docker/php/composer.phar /usr/local/bin/composer
+RUN chmod +x /usr/local/bin/composer
+
 COPY docker/php/php.ini /usr/local/etc/php/conf.d/99-production.ini
 COPY docker/php/opcache.ini /usr/local/etc/php/conf.d/99-opcache.ini