Epic: automated autoscaling release workflow

[Omrigan]

Motivation

A continuation of https://github.com/neondatabase/cloud/issues/9672 and #837

We now have the script, but this is not a final state.

Requirements

Ideally, we want to:

1. Have a button (e. g. in GitHub Actions) so that it is easy to do the deployments without the need to setup local environment to run scripts, etc
2. Have a way to record actions which were taken as a part of a release for an audit
3. Be able to specify a custom roll-out order for components
4. Have codereviews/approvals for ops work
5. Have a machine-readable compatibility matrix (e. g. for #580 and #761)
6. Engineers not from the core autoscaling team during oncall are able to perform most common fixes, like:

• pushing an emergency hotfix to the region
• doing a rollback of a component
• etc

DoD

1. Deployment system covers all regular operational scenarios
2. A subset of features from Requirements

Implementation ideas

1. To have a desired state of things commited into a special branch (e. g. prod) and a idempotent reconciliation process, triggered by a push to that branch.

Tasks

- [ ] Gather info how about how other teams solve this problem
- [ ] Gather info about tools for automating release workflow for k8s
- [ ] https://github.com/neondatabase/autoscaling/issues/888