update CronJob apiVersion

[janfuhrer]

Which chart

mysqldump

What this PR does / why we need it

Following warning occurs if you install the chart:

batch/v1beta1 CronJob is deprecated in v1.21+, unavailable in v1.25+; use batch/v1 CronJob

Update Cronjob API-Version to batch/v1. The new API-Version is available since Kubernetes v1.21, which leads to a breaking change of the helm chart (updated prequisites).

Links

• https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/
• https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.24/#cronjob-v1-batch

Tell me if anything needs to be changed.

Which issue this PR fixes

Special notes for your reviewer

Checklist

• [x] DCO signed
• [x] Chart Version bumped
• [x] All variables are documented in the charts README