Harden React Native iOS Detox CI against simulator shell crashes

[Copilot]

Description

The React Native iOS E2E job is intermittently failing on GitHub-hosted macOS runners due to iOS Simulator instability during Detox teardown/termination. This change makes the workflow more fault-tolerant by isolating build/test phases and resetting simulator state before test execution.

• Workflow hardening (iOS E2E job only)
  • Split the combined Detox iOS step into two explicit phases:
    • detox build --configuration ios.sim.release
    • detox test ... --configuration ios.sim.release
• Simulator state reset before test run
  • Added a dedicated cleanup step in react_native_ci_ios_e2e_tests:
    • xcrun simctl shutdown all || true
    • xcrun simctl erase all || true
    • killall Simulator || true
    • killall com.apple.CoreSimulator.CoreSimulatorService || true
• Detox cleanup on completion
  • Added --cleanup to the Detox test invocation to enforce post-test app/simulator cleanup.
• Scope
  • Kept changes narrowly scoped to .github/workflows/react_native.yml.
  • Preserved existing JUnit output path and artifact upload behavior.

- name: Run Detox iOS e2e Tests
  run: |
    JEST_JUNIT_OUTPUT_FILE=${{ github.workspace }}/js/react_native/e2e/ios-test-results.xml \
      detox test --record-logs all \
                   --configuration ios.sim.release \
                   --loglevel verbose \
                   --take-screenshots failing \
                   --cleanup

Motivation and Context

The failing job pattern shows simulator process instability (failed to terminate ..., system shell probably crashed) rather than deterministic test logic failures. Resetting simulator state before Detox test execution and enforcing cleanup reduces stale/broken simulator carryover and lowers iOS E2E flake rate in CI.