EPIC: Overhaul the release mechanisms for the apps

[ben851]

Description

As a developer of notify, I want our release process to be consistent between staging and development so that I can have a high confidence that production releases will work in the same way staging did.

WHY are we building?

Staging and production release processes differ right now, causing confusion in troubleshooting and also creating risk when doing a production release.

We are migrating to helmfile for the releases, which will require changes to the release process, so we may as well overhaul it all at once.

WHAT are we building?

A release process that can be consistent between staging and production but is automated for staging and requires a button click for production.

VALUE created by our solution

Increased stability, easier to troubleshoot

Acceptance Criteria

• Production and Staging use the same method for releasing
• Staging automatically deploys as it does now
• Production releases are triggered by the PR Bot
• ADR documenting the new release process is completed

QA Steps

• Tested in a realistic production scenario