Add customManagers:dockerfileVersions to renovate.json5 (#30607)

streaming/Dockerfile

@@ -8,6 +8,7 @@ ARG TARGETPLATFORM=${TARGETPLATFORM}
 ARG BUILDPLATFORM=${BUILDPLATFORM}
 
 # Node version to use in base image, change with [--build-arg NODE_MAJOR_VERSION="20"]
+# renovate: datasource=node-version depName=node
 ARG NODE_MAJOR_VERSION="20"
 # Debian image to use for base image, change with [--build-arg DEBIAN_VERSION="bookworm"]
 ARG DEBIAN_VERSION="bookworm"