[charts/redis-ha] Support minReadySeconds in Redis statefulset

[andrewjamesbrown]

What this PR does / why we need it:

Supports minReadySeconds for redis-ha statefulsets; so we can ensure during a rolling update, the specified number of seconds elapses before moving to the next replica.

Note this parameter is only stable in k8s v1.25.

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes #

Special notes for your reviewer:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [ ] DCO signed
• [ ] Chart Version bumped
• [ ] Variables are documented in the README.md
• [ ] Title of the PR starts with chart name (e.g. [stable/mychartname])