fix: 保留 /var/cache/apk 目录结构

- 调整 Dockerfile 清理逻辑，删除后重新创建目录
- 移除 install.sh 中的 /var/cache/apk 清理操作

Co-Authored-By: Claude <noreply@anthropic.com>

Author: houaiai

Dockerfile

@@ -21,7 +21,8 @@ RUN apk add --no-cache --virtual .build-deps \
     && sh install.sh \
     && rm -rf /tmp/extension \
     && apk del .build-deps \
-    && rm -rf /var/cache/apk/* /tmp/* /root/.pearrc /usr/local/include/php
+    && rm -rf /var/cache/apk /tmp/* /root/.pearrc /usr/local/include/php \
+    && mkdir -p /var/cache/apk
 
 # Add Composer (with cache cleanup)
 RUN curl -sS https://getcomposer.org/installer | php \

extension/install.sh

@@ -682,5 +682,4 @@ fi
 
 # Cleanup build artifacts and caches
 echo "---------- Cleanup ----------"
-rm -rf /tmp/* /var/cache/apk/* /root/.pearrc /usr/local/include/php
 docker-php-source delete