[rcr] Fix incorrect output platform

Accidentally copypasted the wrong esbuild config.

compiler/packages/react-compiler-runtime/scripts/build.js

@@ -1,67 +0,0 @@
-#!/usr/bin/env node
-
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-const esbuild = require('esbuild');
-const yargs = require('yargs');
-const path = require('path');
-const {Generator} = require('npm-dts');
-
-const argv = yargs(process.argv.slice(2))
-  .options('w', {
-    alias: 'watch',
-    default: false,
-    type: 'boolean',
-  })
-  .parse();
-
-const config = {
-  entryPoints: [path.join(__dirname, '../src/index.ts')],
-  outfile: path.join(__dirname, '../dist/index.js'),
-  bundle: true,
-  external: ['react'],
-  format: 'cjs',
-  platform: 'node',
-  target: 'es6',
-  banner: {
-    js: `/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @lightSyntaxTransform
- * @noflow
- * @nolint
- * @preventMunge
- * @preserve-invariant-messages
- */
-
-"use no memo";`,
-  },
-};
-
-async function main() {
-  if (argv.w) {
-    const ctx = await esbuild.context(config);
-    await ctx.watch();
-    console.log('watching for changes...');
-  } else {
-    await esbuild.build({
-      sourcemap: true,
-      minify: false,
-      ...config,
-    });
-    await new Generator({
-      entry: 'src/index.ts',
-      output: 'dist/index.d.ts',
-    }).generate();
-  }
-}
-
-main();

compiler/packages/react-compiler-runtime/tsup.config.ts

@@ -9,7 +9,7 @@ export default defineConfig({
   dts: false,
   bundle: true,
   format: 'cjs',
-  platform: 'browser',
+  platform: 'node',
   target: 'es2015',
   banner: {
     js: `/**