⚰️(backend) remove unused setup file

We are now using pyproject.toml, cleaned legacy files that weren't removed
when bootstraping the project.

src/backend/setup.py

@@ -1,7 +0,0 @@
-#!/usr/bin/env python
-"""Setup file for the meet module. All configuration stands in the setup.cfg file."""
-# coding: utf-8
-
-from setuptools import setup
-
-setup()