Support for Kubernetes v1.28

[oliver-goetz]

How to categorize this PR?

/area open-source usability /kind enhancement /platform equinix-metal /exp intermediate /topology garden seed shoot /merge squash

What this PR does / why we need it: This PR adds support for Kubernetes 1.28 to the extension.

Which issue(s) this PR fixes: Part of https://github.com/gardener/gardener/issues/8291

Special notes for your reviewer:

• I have successfully validated the functionality as follows:
  • :white_check_mark: Create new clusters with versions < 1.28
  • :white_check_mark: Create new clusters with version = 1.28
  • :white_check_mark: Upgrade old clusters from version 1.27 to version 1.28
  • :white_check_mark: Delete clusters with versions < 1.28
  • :white_check_mark: Delete clusters with version = 1.28

/cc @schrodit could you please test cluster creation etc. enlisted before. I don't have any environment to do so.

Release note:

The provider-equinix-metal extension does now support shoot clusters with Kubernetes version 1.28. You should consider the [Kubernetes release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.28.md) before upgrading to 1.28. 

[schrodit]

/cc @schrodit could you please test cluster creation etc. enlisted before. I don't have any environment to do so.

will do a test and approve/merge once tested

[oliver-goetz]

Thanks 👍

[gardener-robot]

@schrodit, @jonas-zipprick You have pull request review open invite, please check

[schrodit]

was now able to test it. And it works fine with Gardener 1.80