`helmExecute` - support multiple source repositories

[mpern]

To ensure reproducible deployments with helm chart repositories during CD, you need to run helm dependencies build to ensure to use the charts as defined in the Chart.lock file.

https://helm.sh/docs/helm/helm_dependency_build/

To use build, you need to register the chart repository beforehand, otherwise it is rejected for security reasons (see helm/helm/issues/8036 for details).

At the moment helmExecute only supports a single chart repository (sourceRepository* parameters) which is not enough for more complex deployments which can depend on multiple repositories.

• Please support an array of sourceRepositories
• helm repo add all repositories in the array before executing the configured dependency command.