chore: Enforce Helm "--atomic" standard across helm packages and CI

[stevenplatt]

Currently, the --atomic flag is not used with helm installs in a number of places.

Removing the flag allows easier debugging (because helm doesn't wait for all health checks to clear).

Not using it in automations such as CI however can lead to test and deployment flakiness, as helm will allow automations to progress before the underlying deployment is in a healthy state. Or the deployment appears successful, even when it has components that have failed.