🦙 Ollamate: Align environment handling to AP UI

[Gary-H9]

Purpose

The approach of ollamate should mirror analytical-platform-ui wherever possible.
The purpose of this ticket is to align the approach taken when consuming environment variables locally.

At the moment ollamate uses django-environ==0.11.2 but ui uses python-dotenv==1.0.1.

Definition of Done

• Convert ollamate to use python-dotenv==1.0.1 as the UI uses

[Gary-H9]

This work is on hold / abandoned whilst work elsewhere in the business goes on.