[release/v13] Support Openstack Server Groups to ensure affinity

[github-actions]

Backport #1981 to release/v13 for #1982

Copied from PR:

Addresses #1701

release/v13

Description

Adding support to the Openstack Cloud Provider used within the rancher2_machine_config_v2 resource

Testing

I have forked this and created a provider under https://search.opentofu.org/provider/geoffr/rancher2/latest and tested both the id and names for the server group successfully on a deployed Rancher RKE2 cluster.

As these are optional fields this is not a breaking change.

[github-actions]

New Release Candidate Available for Validation: v13.2.0-rc.2

[github-actions]

New Release Candidate Available for Validation: v13.2.0-rc.3

[github-actions]

New Release Candidate Available for Validation: v13.2.0-rc.4

[github-actions]

New Release Candidate Available for Validation: v13.2.0-rc.10

[github-actions]

New Release Candidate Available for Validation: v13.5.0-rc.1

[matttrach]

Per internal conversation, this is approved for release based on community testing.
We are trusting @geoffr and his team, thank you so much for your contributions!