Upgrade RN CLI to v8 alpha (#33610)

Summary:
Upgrades the React Native CLI to v8 alpha. This version removes manual linking configuration and a few other things, hence changes to the project configuration.

cc kelset fortmarek

## Changelog

[General] [Changed] - Upgrade RN CLI to v8 alpha

Pull Request resolved: #33610

Test Plan: CI green.

Reviewed By: rubennorte

Differential Revision: D35547624

Pulled By: cortinico

fbshipit-source-id: 4de9f280f9d1949c94057c32568b3fdfa4ee6a73

package.json

@@ -94,9 +94,9 @@
   },
   "dependencies": {
     "@jest/create-cache-key-function": "^27.0.1",
-    "@react-native-community/cli": "^7.0.3",
-    "@react-native-community/cli-platform-android": "^7.0.1",
-    "@react-native-community/cli-platform-ios": "^7.0.1",
+    "@react-native-community/cli": "^8.0.0-alpha.0",
+    "@react-native-community/cli-platform-android": "^8.0.0-alpha.0",
+    "@react-native-community/cli-platform-ios": "^8.0.0-alpha.0",
     "@react-native/assets": "1.0.0",
     "@react-native/normalize-color": "2.0.0",
     "@react-native/polyfills": "2.0.0",

react-native.config.js

@@ -16,12 +16,10 @@ module.exports = {
   commands: [...ios.commands, ...android.commands],
   platforms: {
     ios: {
-      linkConfig: ios.linkConfig,
       projectConfig: ios.projectConfig,
       dependencyConfig: ios.dependencyConfig,
     },
     android: {
-      linkConfig: android.linkConfig,
       projectConfig: android.projectConfig,
       dependencyConfig: android.dependencyConfig,
     },
@@ -32,7 +30,7 @@ module.exports = {
   reactNativePath: '.',
   project: {
     ios: {
-      project: './packages/rn-tester/RNTesterPods.xcworkspace',
+      sourceDir: './packages/rn-tester',
     },
     android: {
       sourceDir: './packages/rn-tester',