Remove NODE_ENV check

Motivation: tj#1955

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`.
@@ -905,7 +903,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
 
   _parseSubroutine(async, userArgsCallback, argv, parseOptions) {
     const methodName = async ? 'parseAsync' : 'parse';
-    if (!PRODUCTION && this.parent) {
+    if (this.parent) {
       console.warn(`Called .${methodName}() on subcommand '${this._name}'.
 Call on top-level command instead`);
     }
@@ -934,7 +932,7 @@ Call on top-level command instead`);
   parse(argv, parseOptions) {
     return this._parseSubroutine(false, (userArgs) => {
       const result = this._parseCommand([], userArgs);
-      if (!PRODUCTION && isThenable(result)) {
+      if (isThenable(result)) {
         console.warn(`.parse() is incompatible with async hooks and actions.
 Use .parseAsync() instead.`);
       }