Update x509 updater to a k8s CronJob

[ponyisi]

Fixes #453

[Copilot]

Pull Request Overview

This PR converts the x509 certificate updater from a Kubernetes Deployment to a CronJob that runs every 6 hours. The change addresses issue #453 by implementing a more appropriate scheduling mechanism for periodic certificate updates.

• Added a --loop argument to control whether the updater runs continuously or exits after one execution
• Modified the Python script to exit after the first pass when not in loop mode
• Changed the Kubernetes resource from Deployment to CronJob with a 6-hour schedule

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
x509_secrets/x509_updater.py	Added loop argument and conditional exit logic for single-run execution
helm/servicex/templates/x509-secrets/deployment.yaml	Converted from Deployment to CronJob with 6-hour schedule

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[gordonwatts]

This looks great to me - though I think Ben should probably approve!