Filter out witness node when creating cluster network config (WIP, Under Testing)

[a110605]

Summary

As per discussed with @Vicente-Cheng , we should filter out witness node when creating network config.

PR Checklist

• Is this a multi-tenancy feature/bug?
  • [ ] Yes, the relevant RBAC changes are at:
• Do we need to backport changes to the old Rancher UI, such as RKE1?
  • [ ] Yes, the relevant PR is at:
• Are backend engineers aware of UI changes?
  • [x] Yes, the backend owner is: @Vicente-Cheng

Fixes #

[BUG] Unable to select NIC to create network config when cluster contains witness node

Screenshot/Video

1 default + 1 witness node

2 default + 1 witness node