K8s 1.37 client go / envtest updates

[marosset]

Why are these changes needed?

K8s v1.37 is out and this is also a prereq for continues the WAS work to support K8s v1.37 scheduling APIS

This PR updates client-go and envtest targets to K8s v1.37 in all packages in the repo (including podpool and historyserver)

A few notes:

• The v1alpha2 scheduling API was removed in K8s v1.37 and in order to maintain support for K8s v1.36 clusters this PR vendors local copies of the v1alpha2 scheduling API into the repo. There is a README.md in the PR with more details.
• I fixed an issue with the historyserver makefile which was causing which was causing files to not get formatted so that changes are also included.

Related issue number

Labels

• If this PR has user-facing changes that require documentation updates at release time, I have added the doc-updates-required label.
• If this PR contains breaking changes, I have added the breaking-change label.

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • This PR is not tested :(

Manual test instructions

[rueian]

Actually, I think we can move to scheduling.k8s.io/v1alpha3 directly. We can ask users to keep using the old kuberay if they require k8s.io/api/scheduling/v1alpha2.

[machichima]

Agree, we do not need to copy the whole type here

[marosset]

I would need to update things like the kindconfig used in CI for the v1alpha2 e2e test job and things if we want to switch the current WAS plugin too (and maybe a few other things)

I think it might be cleaner to just keep the v1alpha2 files around for now.
If you all are really against this I can do testing for the v1alpha3 support and include that here.
Let me know!

[win5923]

+1 move to scheduling.k8s.io/v1alpha3

[machichima]

Yes I think we can move to v1alpha3 in this PR, as v1alpha2 files will eventually be removed (either this or follow-up PR), we can just do that here

[marosset]

ok! let me work on that and i'll update this PR

[marosset]

I updated all the existing v1alpha2 references to v1alpha3 but DID NOT change any behaviors.

I have work done in another branch to implement support for new behaviors (specifically support mutable PodGroup minCount / enable WAS for autoscaling clusters and support for PodGroupPremptionPolicy)).
After this merges I'll rebase those changes on here and open up a new PR.

cc @rueian @machichima @win5923