infra(e2e): fix enabling new arch for RNTester iOS in the E2E script (#34882)

Summary:
Quick follow up to https://github.com/facebook/react-native/pull/34513 to fix an issue that has been bothering the release crew for a while: the iOS new arch component not working! Turns out, we're silly billies �

## Changelog

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[Internal] [Changed] - Add new arch flag to iOS pod install command in E2E script

Pull Request resolved: https://github.com/facebook/react-native/pull/34882

Test Plan:
Everything works correctly now:

<img width="987" alt="Screenshot 2022-10-06 at 14 20 09" src="https://user-images.githubusercontent.com/16104054/194327768-4da7d607-879b-46ad-a453-504983980831.png">

Reviewed By: dmytrorykun

Differential Revision: D40143251

Pulled By: dmytrorykun

fbshipit-source-id: 91ba6e22c25770efe6a839d6728d7052bc17a8f2

scripts/test-e2e-local.js

@@ -74,12 +74,12 @@ if (argv.target === 'RNTester') {
     console.info(
       `We're going to test the ${
         argv.hermes ? 'Hermes' : 'JSC'
-      } version of RNTester iOS`,
+      } version of RNTester iOS with the new Architecture enabled`,
     );
     exec(
       `cd packages/rn-tester && USE_HERMES=${
         argv.hermes ? 1 : 0
-      } bundle exec pod install --ansi`,
+      } RCT_NEW_ARCH_ENABLED=1 bundle exec pod install --ansi`,
     );
 
     // if everything succeeded so far, we can launch Metro and the app
@@ -98,7 +98,7 @@ if (argv.target === 'RNTester') {
     console.info(
       `We're going to test the ${
         argv.hermes ? 'Hermes' : 'JSC'
-      } version of RNTester Android`,
+      } version of RNTester Android with the new Architecture enabled`,
     );
     exec(
       `./gradlew :packages:rn-tester:android:app:${