fix(DEV_SSR): set NODE_ENV to production for render-html worker process instead of pointing externals to production react (#29620)

* fix(gatsby): fix DEV_SSR by only setting react-dom/server to use prod version

* Just set NODE_ENV to production

Author: KyleAMathews

packages/gatsby/src/utils/dev-ssr/render-dev-html.ts

@@ -2,6 +2,7 @@ import JestWorker from "jest-worker"
 import fs from "fs-extra"
 import { joinPath } from "gatsby-core-utils"
 import report from "gatsby-cli/lib/reporter"
+import { isCI } from "gatsby-core-utils"
 
 import { startListener } from "../../bootstrap/requires-writer"
 import { findPageByPath } from "../find-page-by-path"
@@ -13,7 +14,15 @@ const startWorker = (): any => {
   const newWorker = new JestWorker(require.resolve(`./render-dev-html-child`), {
     exposedMethods: [`renderHTML`, `deleteModuleCache`, `warmup`],
     numWorkers: 1,
-    forkOptions: { silent: false },
+    forkOptions: {
+      silent: false,
+      env: {
+        ...process.env,
+        NODE_ENV: isCI() ? `production` : `development`,
+        forceColors: true,
+        GATSBY_EXPERIMENTAL_DEV_SSR: true,
+      },
+    },
   })
 
   // jest-worker is lazy with forking but we want to fork immediately so the user

packages/gatsby/src/utils/webpack.config.js

@@ -692,20 +692,8 @@ module.exports = async (
         // User modules that do not need to be part of the bundle
         if (userExternalList.some(item => checkItem(item, request))) {
           // TODO figure out to make preact work with this too
-          let modifiedRequest = request
-          if (
-            stage === `develop-html` &&
-            isCI() &&
-            process.env.GATSBY_EXPERIMENTAL_DEV_SSR
-          ) {
-            if (request === `react`) {
-              modifiedRequest = `react/cjs/react.production.min.js`
-            } else if (request === `react-dom/server`) {
-              modifiedRequest = `react-dom/cjs/react-dom-server.node.production.min.js`
-            }
-          }
 
-          resolver(context, modifiedRequest, (err, newRequest) => {
+          resolver(context, request, (err, newRequest) => {
             if (err) {
               callback(err)
               return