Use Renovate to update redis-ha chart

[crenshaw-dev]

Summary

Updating the redis-ha chart requires bumping a version in manifests/ha/base/redis-ha/chart/requirements.yaml and then running both manifests/ha/base/redis-ha/generate.sh and make manifests-local.

Motivation

Upgrading the chart is currently a manual task that's often forgotten between releases and then difficult to pick up for new devs.

Proposal

I don't know enough about Renovate to be sure, but looks like Renovate can run commands before committing its update. Also looks like it supports requirement.yaml bumps.