Update React Native iOS CI build. (#25967)

### Description
<!-- Describe your changes. -->

Update React Native iOS CI build.
- Split iOS package build, unit test, and E2E test into separate jobs.
The finer granularity allows for more parallelism and the ability to
re-run a specific test job without also rebuilding the package in case
of failure due to test flakiness.
- Fix issue with Detox not actually running the E2E tests on iOS due to
an earlier failure. The issue was resolved by upgrading to version
20.11.4. It's not obvious why this wasn't causing the CI build to fail
consistently.
- This is the Detox fix:
wix/Detox@f72e0f3
- Reduce iOS package build time by not building ORT test code. ORT unit
tests are already run on the iOS simulator in another CI build.

### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->

CI pipeline improvements.

Author: edgchen1