Workaround RNReanimated pod install failure

[mokagio]

Closed in favor of #5912, which implements all of this changes and support toggling the Hermes engine.

---

Points RNReanimated to a custom branch to work around 2.17.0 issue

The issue is due to RNReanimated looking for react-native in the node_modules relative to its location, which is how most projects would be setup. Unfortunately, our projects is not standard.

When running pod install or pod update, we'd get:

    Installing RNReanimated 2.17.0 (was 2.9.1-wp-4)
    internal/modules/cjs/loader.js:934
      throw err;
      ^
    
    Error: Cannot find module 'react-native/package.json'
    Require stack:
    - /Users/gio/Developer/a8c/gutenberg-mobile/ios-xcframework/[eval]
        at Function.Module._resolveFilename (internal/modules/cjs/loader.js:931:15)
        at Function.resolve (internal/modules/cjs/helpers.js:113:19)
        at [eval]:1:9
        at Script.runInThisContext (vm.js:134:12)
        at Object.runInThisContext (vm.js:310:38)
        at internal/process/execution.js:81:19
        at [eval]-wrapper:6:22
        at evalScript (internal/process/execution.js:80:60)
        at internal/main/eval_string.js:27:3 {
      code: 'MODULE_NOT_FOUND',
      requireStack: [
        '/Users/gio/Developer/a8c/gutenberg-mobile/ios-xcframework/[eval]'
      ]
    }
    
    [!] Invalid `RNReanimated.podspec` file: no implicit conversion of nil into String.
    
     #  from /var/folders/dq/cdqxvx3s5ps75564rpmb_dc00000gn/T/d20230627-89428-abwplk/RNReanimated.podspec:5
     #  -------------------------------------------
     #  reanimated_package_json = JSON.parse(File.read(File.join(__dir__, "package.json")))
     >  config = find_config()
     #  assert_no_multiple_instances(config)
     #  -------------------------------------------

[peril-wordpress-mobile]

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[mokagio]

I think this can be removed now. Most likely, the problem in CI was that we didn't have the node_modules

[mokagio]

Closing in favor of #5912, which implements all of this changes and support toggling the Hermes engine.