PodDisruptionBudget: use the new policy/v1 api

[a7i]

Note: Samson is a public repo, do not include Zendesk-internal information, urls, etc.

• Add description: policy/v1beta1 PodDisruptionBudget is deprecated in v1.21+, unavailable in v1.25+
• Add screenshots when changing: the UI N/A
• Add unit tests: N/A

References

• Jira link: N/A

Risks

• Low, if a cluster is using a version older than v1.21, it will break

[grosser]

https://github.com/zendesk/samson/pull/4019 to fix vuln