fix: upgrade @kubernetes/client-node from 0.20.0 to 0.21.0

Snyk has created this PR to upgrade @kubernetes/client-node from 0.20.0 to 0.21.0.

See this package in npm:
@kubernetes/client-node

See this project in Snyk:
https://app.snyk.io/org/cloud-container_integration/project/2214bcc1-611e-4919-a1cb-9f310abc65d2?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot