[ci] add github workflow to the bump version of an Chart version

[jkroepke]

What this PR does / why we need it

xref: #4292

This PR continues the integration of Renovate into this repository. Unfortunately, Renovate cannot automatically bump the Helm chart version for changes made in the values files.

To address this, a support workflow has been added, which uses GitHub Actions to bump the version.

Additionally, the renovate.json file is configured to group version bumps by chart directory. Custom managers have been added from our internal company repository. These custom managers allow developers to enable automated dependency updates by adding Renovate annotations, using code comments. The regex patterns include common use cases, such as the following example:

helm-charts/charts/kube-prometheus-stack/values.yaml

Lines 708 to 711 in 7c7bc2e

	image:
	registry: quay.io
	repository: prometheus/alertmanager
	tag: v0.28.0

Once worked, the next iteration is extend the renovate-bump-chart-version workflow to run the hack/update*sh scripts.

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

• DCO signed
• Chart Version bumped
• Title of the PR starts with chart name (e.g. [prometheus-couchdb-exporter])