Add support for the sleep pre-stop lifecycle action

[Tenzer]

Rollback Plan

If a change needs to be reverted, we will publish an updated version of the library.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.

No

Description

This adds support for the sleep action as a pre-stop lifecycle hook. It was graduated to be stable functionality with Kubernetes 1.34:
https://kubernetes.io/blog/2025/08/27/kubernetes-v1-34-release/#sleep-action-for-container-lifecycle-hooks
kubernetes/enhancements#3960

Acceptance tests

• Have you added an acceptance test for the functionality being added?
• Have you run the acceptance tests on this branch?

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccXXX'

...

Release Note

Release note for CHANGELOG:

Add support for the "sleep" action as a pre-stop lifecycle hook

References

Community Note

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[hashicorp-cla-app]

Thank you for your submission! We require that all contributors sign our Contributor License Agreement ("CLA") before we can accept the contribution. Read and sign the agreement

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[Tenzer]

I haven't run tests yet, as I'd like to get confirmation that this is approximately the right set of changes to make for this. Also, it looks like there's only tests for the exec pre-stop lifecycle hook at the moment. Perhaps it's worthwhile adding tests for all four variants?

Also, how are docs updated? Are they handled manually or generated from some source?