Remove BuildBot configuration code needed for systemd setup

Previously when Production was running on systemd services, we couldn't use the .env files defined in the project tree because they were specifically designed for usage in docker-compose.

This led to hard coding variable defaults in the buildbot code, in the form of os.getenv(#env_variable_for_containers#, default=#default_for_systemd#)

In this task:

• > switch to a fail proof approach of loading variables using os.environ which will raise a key error exception if the environment variable is not defined
  -> adapt the GitHub CI script validate_masters to load the environment variables for each environment << dev , prod >>
  -> remove "systemd" approach of loading PORTS for masters.