Export script/cocoapods/flipper.rb to fix the CI (#33792)

Summary:
Pull Request resolved: #33792

This Diff exports the `flipper.rb` file in the `package.json` to fix the OSS CI

## Changelog
[iOS][Changed] - Export `flipper.rb` script file

Reviewed By: cortinico

Differential Revision: D36244721

fbshipit-source-id: d8c57ce6525bce6f0acbe722064b79eda0d0a7a8

package.json

@@ -53,6 +53,7 @@
     "scripts/react_native_pods_utils/script_phases.rb",
     "scripts/react_native_pods_utils/script_phases.sh",
     "scripts/react_native_pods.rb",
+    "scripts/cocoapods/flipper.rb",
     "scripts/react-native-xcode.sh",
     "sdks/hermesc",
     "sdks/hermes-engine.podspec",