Docker File Update

[Manav-bin]

Description of Changes

Replaced the Alpine-based multi-stage Docker build with a Debian python:3.9-slim multi-stage build to improve compatibility with prebuilt wheels, reduce build complexity, and avoid musl-related compilation issues.

Fixes #XXX.

Please note any noqa: comments needed to appease flake8.

Major Changes Implemented:

• Replaced python:3.9-alpine base images with python:3.9-slim for both builder and final stages
• Removed Alpine-specific dependencies (apk, alpine-sdk, musl-dev, linux-headers, etc.)
• Added Debian equivalents (build-essential, libffi-dev, libssl-dev, cargo) in the builder stage
• Simplified artifact copying by copying /usr/local from the builder stage into the final stage
• Limited runtime dependencies in final stage to libstdc++6 only
• Retained plugin pre-download step (pwncat-cs --download-plugins) in final stage

Pre-Merge Tasks

• [x ] Formatted all modified files w/ python-black
• Sorted imports for modified files w/ isort
• Ran flake8 on repo, and fixed any new problems w/ modified files
• Ran pytest test cases
• Added brief summary of updates to CHANGELOG (under [Unreleased])