chore(deps): update dependency helm/helm to v3.16.4

Install helm plugin helm-values-schema-json to generate a values.schema.json from multiple sources.

Dockerfile

@@ -5,13 +5,14 @@ ARG HELM_VERSION
 RUN apk add bash curl git openssl && \
     curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 --output /tmp/install.sh
 
-RUN [[ ${HELM_VERSION} == "" ]]; bash /tmp/install.sh
+RUN if [[ -z "${HELM_VERSION+x}" ]]; then bash /tmp/install.sh; fi
-RUN [[ ${HELM_VERSION} != "" ]]; bash /tmp/install.sh --version ${HELM_VERSION}
+RUN if [[ -n "${HELM_VERSION+x}" ]]; then bash /tmp/install.sh --version "${HELM_VERSION}"; fi
 
 RUN rm /tmp/install.sh
 
 # Install additionally helm plugins
 RUN helm plugin install https://github.com/chartmuseum/helm-push.git && \
-    helm plugin install https://github.com/helm-unittest/helm-unittest.git
+    helm plugin install https://github.com/helm-unittest/helm-unittest.git && \
+    helm plugin install https://github.com/losisin/helm-values-schema-json.git
 
 ENTRYPOINT [ "/usr/local/bin/helm" ]

Makefile

@@ -1,6 +1,6 @@
 # HELM_VERSION
 # Only required to install a specifiy version
-HELM_VERSION?=v3.16.3 # renovate: datasource=github-releases depName=helm/helm
+HELM_VERSION?=v3.16.4 # renovate: datasource=github-releases depName=helm/helm
 
 # CONTAINER_RUNTIME
 # The CONTAINER_RUNTIME variable will be used to specified the path to a