Update Helm version to latest

[codeclown]

Helm-playground is currently based on v3.14.0:

https://github.com/shipmight/helm-playground/blob/master/go.mod#L3-L4

At the time of writing, the latest Helm version is v3.17.0.

There are some new templating features in the newest version, e.g. toYamlPretty