Fix/reduced docker image size

[felixivance]

• used python:3.8.3-alpine as the base image, which is smaller than python:3.8.3-slim.
• combined the apk add commands to install build tools and dependencies into a single RUN instruction to reduce the number of layers.
• removed build tools and packages using rm -rf /var/cache/apk/* to clean up the image and reduce its size.