external-dns-helm-chart-1.16.0

Added

• Add helm testing framework helm plugin unittest. (#5137) @ivankatliarchuk
• Add ability to generate schema with helm plugin schema. (#5075) @ivankatliarchuk
• Add docs/contributing/dev-guide.md#helm-values guide. (#5075) @ivankatliarchuk

Changed

• Regenerate JSON schema with `helm-values-schema-json' plugin. (#5075) @ivankatliarchuk
• Update ExternalDNS OCI image version to v0.16.1. (#xxxx) @stevehipwell