Move api server in helm chart back to beta with _ before it

[andrii-korotkov-verkada]

Description

The apiServer is now a main entry in the helm chart. Make it beta with _ prefix and reinstate the warning. See #44463 for reference.

Use case/motivation

It may change in between upcoming 1.16.0 and Airflow 3 release, so better to keep it beta to allow more flexibility.

Related issues

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[jedcunningham]

@andrii-korotkov-verkada - so you know in the future, issues are entirely optional, you can just open a PR directly.

[andrii-korotkov-verkada]

Ah okay, sounds good.