[SE-5427] refactor: remove the director instance
Description
This PR ensures that the DigitalOcean provider-based build flow passes. The change also removes the director instance as that's not needed at all.
Redis
The managed Redis cluster for DO was replaced by a helm chart, as managed Redis has no ACL support. Since the Redis user creation is not supported natively by DO, we have to do that using a helper script. The script creates the Redis users one by one, and sets the correct ACLs.
Testing instructions
Since the goal of this PR and the related ticket is to test the DO integration, I think it is enough to check that the related pipeline has passed the tests.
Notes
Please note that this PR is not responsible for ensuring the instance is working properly. That part is blocked on multiple things and will be resolved by a follow-up ticket (among other things). To ensure the instance is working properly will be the responsibility of that ticket.
The work here contains another MR: !47 (merged)