Fix eager rs deletion

[mortenzwarenstein]

Description

Fixed a bug where replicasets would get deleted before the new one was ready.
Left replicaset scaling to kubernetes, cleans up old replicaset's resources when replicasets are scaled down.

Type of change

• Bugfix

Checklist:

• I've double-checked the code in this PR myself
• I've left the code better than before (boy scout rule)
• The code is readable, comments are added that explain hard or non-obvious parts.
• I've expanded/improved the (unit) tests, when applicable
• I've run (unit) tests that prove my solution works
• There's no sensitive information like credentials in my PR