SubFamilyFlexible calculations should ensure that instance types have the same supported architectures.

[backjo]

Is this a BUG REPORT or FEATURE REQUEST?:
BUG REPORT
What happened:
I configured an InstanceGroup to use spot instances with the SubFamilyFlexible option, with the main instance type being set to m6i.2xlarge. Instance Manager also included m6g.2xlarges in the ASG, which have a different supported architecture (arm64) then the main instance type (amd64)
What you expected to happen:
Only instances with the same architecture should be used.
How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Kubernetes version:

kubectl version -o yaml

Other debugging information (if applicable):

• InstanceGroup status:

kubectl describe instancegroup <ig-name>

• controller logs:

kubectl logs <instance-manager pod>