Remove redundant ways to load environment variables

[dennyabrain]

Which feature or component needs enhancement?
The way we manage environment variables in the project

Describe the current behavior
We seem to have two redundant approaches to loading environment variables from the *.env files.

kaapi-guardrails/backend/app/core/config.py

Line 94 in 1d62fc2

def get_settings() -> Settings:

and

kaapi-guardrails/backend/app/load_env.py

Line 5 in 1d62fc2

def load_environment():

Describe the enhancement you'd like
The settings variable exposed in config.py seems to be the one we are relying heavily on throughout the codebase. So we can remove the load_env.py and all calling code referencing that file.

Why is this enhancement needed?
This will prevent confusing overrides of environment variables due to the two approaches interacting in unexpected manner.