chore(deps): update dependency helm/helm to v4

Dockerfile

@@ -3,11 +3,16 @@ FROM docker.io/library/alpine:3.22.2
 ARG HELM_VERSION
 
 RUN apk add bash curl git openssl && \
-    curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-4 --output /tmp/install.sh
+    curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 --output /tmp/install.sh
 
 RUN if [[ -z "${HELM_VERSION+x}" ]]; then bash /tmp/install.sh; fi
 RUN if [[ -n "${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/losisin/helm-values-schema-json.git
+
 ENTRYPOINT [ "/usr/local/bin/helm" ]