chore(react-native-codegen): Remove fixtures and outdated transforms from build output (#49916)

Summary:
- Update ignore micromatch pattern to filter out `__test_fixtures__` from build output
- Remove `babel/plugin-transform-object-rest-spread`
- Remove `babel/plugin-transform-async-to-generator`
- Remove `babel/plugin-transform-destructuring`

The `package.json:engines:node` field is already set to `>=18` which makes the three Babel transforms that were removed redundant.

## Changelog:

[INTERNAL] [CHANGED] - Remove fixtures files and outdated Babel transforms from `react-native/codegen` build output

Pull Request resolved: https://github.com/facebook/react-native/pull/49916

Test Plan: - Ran against Node 18

Reviewed By: robhogan

Differential Revision: D70885090

Pulled By: cortinico

fbshipit-source-id: 328b75a6031a7ca6a9b3ed170061ffb0a47d6d93

packages/react-native-codegen/.babelrc

@@ -1,8 +1,5 @@
 {
   "plugins": [
-    "@babel/plugin-transform-object-rest-spread",
-    "@babel/plugin-transform-async-to-generator",
-    "@babel/plugin-transform-destructuring",
     "@babel/plugin-transform-flow-strip-types",
     "@babel/plugin-syntax-dynamic-import",
     "@babel/plugin-transform-class-properties",

packages/react-native-codegen/package.json

@@ -38,12 +38,9 @@
   "devDependencies": {
     "@babel/core": "^7.25.2",
     "@babel/plugin-syntax-dynamic-import": "^7.8.3",
-    "@babel/plugin-transform-async-to-generator": "^7.24.7",
     "@babel/plugin-transform-class-properties": "^7.25.4",
-    "@babel/plugin-transform-destructuring": "^7.24.8",
     "@babel/plugin-transform-flow-strip-types": "^7.25.2",
     "@babel/plugin-transform-nullish-coalescing-operator": "^7.24.7",
-    "@babel/plugin-transform-object-rest-spread": "^7.24.7",
     "@babel/plugin-transform-optional-chaining": "^7.24.8",
     "@babel/preset-env": "^7.25.3",
     "chalk": "^4.0.0",

packages/react-native-codegen/scripts/build.js

@@ -36,7 +36,7 @@ const prettierConfig = JSON.parse(
 const SRC_DIR = 'src';
 const BUILD_DIR = 'lib';
 const JS_FILES_PATTERN = '**/*.js';
-const IGNORE_PATTERN = '**/__tests__/**';
+const IGNORE_PATTERN = '**/(__tests__|__test_fixtures__)/**';
 const PACKAGE_DIR = path.resolve(__dirname, '../');
 
 const fixedWidth = str => {