fix(hetzner): deprecated server type will break on 2024-09-06

[apricote]

What type of PR is this?

/kind bug
/kind cleanup

What this PR does / why we need it:

The cx11 server type was deprecated on 2024-06-06 and will be removed from the API on 2024-09-06. Once it is removed, the cluster-autoscaler provider hetzner will fail every main loop with with the following error messages:

mixed_nodeinfos_processor.go:160] Unable to build proper template node for draining-node-pool: failed to create resource list for node group draining-node-pool error: failed to get machine type cx11 info error: server type not found
static_autoscaler.go:387] Failed to get node infos for groups: failed to create resource list for node group draining-node-pool error: failed to get machine type cx11 info error: server type not found

The server type is hardcoded in the draining-node-pool, which was used in the OG PR #3640 but unused in the second PR #3838 that was actually merged.

As the draining-node-pool is unused since the first release of this provider, I have opted to remove it altogether. In theory this is a user visible change, as this node pool is visible through the status config map

Which issue(s) this PR fixes:

Fixes #7210

Special notes for your reviewer:

We would like to back port this change to all actives releases ASAP. If you think this change does not qualify for a back port, I am happy to submit a different PR that only changes the hardcoded server type to one that will be available for longer.

This one is one me. I should have noticed this reference when checking our projects for hardcoded cx11 references when the deprecation was announced.

Does this PR introduce a user-facing change?

Fix Hetzner Provider not starting after 2024-09-07

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

- [Hetzner Cloud Changelog](https://docs.hetzner.cloud/changelog#2024-06-06-old-server-types-with-shared-intel-vcpus-are-deprecated)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: apricote, jooola

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• cluster-autoscaler/cloudprovider/hetzner/OWNERS [apricote]

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[apricote]

@Shubham82 @x13n Could you take a look at this? We would really appreciate it if we can get this in the next patch releases.

---

Sorry to keep annoying you with our PRs. We have a new colleague starting in our team to work on our Kubernetes integrations, so I am optimistic that we can get the second owner in the coming months.

[Shubham82]

We would like to back port this change to all actives releases ASAP. If you think this change does not qualify for a back port, I am happy to submit a different PR that only changes the hardcoded server type to one that will be available for longer.

@apricote, IMO we can backport this in the supported CA version also.

[Shubham82]

/lgtm

[apricote]

Thanks @Shubham82!

I am working on the backports.

[apricote]

Backports:

• [v1.31] fix(hetzner): deprecated server type will break on 2024-09-06 #7298
• [v1.30] fix(hetzner): deprecated server type will break on 2024-09-06 #7299
• [v1.29] fix(hetzner): deprecated server type will break on 2024-09-06 #7300
• [v1.28] fix(hetzner): deprecated server type will break on 2024-09-06 #7301