Configure redis node name without throwing an exception at build time

config/prod.exs

@@ -19,7 +19,7 @@ config :explorer, ExplorerWeb.Endpoint,
   force_ssl: [rewrite_on: [:x_forwarded_proto]],
   cache_static_manifest: "priv/static/cache_manifest.json",
   secret_key_base: Map.fetch!(System.get_env(), "SECRET_KEY_BASE"),
-  pubsub: [adapter: Phoenix.PubSub.Redis, url: Map.fetch!(System.get_env(), "REDIS_URL"), node_name: Map.fetch!(System.get_env(), "HEROKU_DYNO_ID")]
+  pubsub: [adapter: Phoenix.PubSub.Redis, url: Map.fetch!(System.get_env(), "REDIS_URL"), node_name: System.get_env("DYNO")]
 
 # Do not print debug messages in production
 config :logger, level: :info