Update autoscaler for labels and taints

Background

The contribution of the scale from zero feature  to the upstream autoscaler inadvertently included a portion of code that only works on OpenShift's Machine API. This code is about propagating Labels and Taints during scale from zero operations.

This functionality has been proposed for removal , when OpenShift rebases on the 1.26 autoscaler it will need to re-add this functionality as it was previously in OpenShift. This will need to be carried going forward to ensure that our implementation continues to function as normal.

This code is not appropriate for the upstream because it is not specifically about Cluster API but the OpenShift variant Machine API.

For reference, this is how the code appears in 4.11  , this pattern should be carried as well as the related unit tests.

Steps

• Create a patch for Machine API specific behavior of Labels and Taints interface functions
• Update unit tests

Stakeholders

• cloud team

Definition of Done

• Cluster autoscaler continues to work as expected on OpenShift

• Docs

• n/a

• Testing

• Current tests exercise this functionality and should continue to work