Remove NODE_ENV check

Motivation: tj#1955

Author: aweebit

lib/command.js

@@ -12,8 +12,6 @@ const { suggestSimilar } = require('./suggestSimilar');
 
 // @ts-check
 
-const PRODUCTION = process.env.NODE_ENV === 'production';
-
 class Command extends EventEmitter {
   /**
    * Initialize a new `Command`.
@@ -940,7 +938,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
 
   _parseSubroutine(async, userArgsCallback, argv, parseOptions) {
     const methodName = async ? 'parseAsync' : 'parse';
-    if (!PRODUCTION && this._implicitlyCreated) {
+    if (this._implicitlyCreated) {
       console.warn(`Called .${methodName}() on subcommand '${this._name}' added with .command().
 Call on top-level command instead`);
     }