Declare RNTester test pod dependencies for dynamic frameworks

[kunal26das]

Summary

RNTester's test pod uses ObjCTurboModule and the selected JavaScript engine but does not declare their providing pods as direct dependencies. When building RNTester from source with dynamic frameworks, React-RCTTest fails to link those symbols.

This native fork PR mirrors the upstream RNTester dependencies submission as layer 2 of six. This layer is based on KMP foundation. The registered fork stack uses dependent PR bases, so this PR shows its incremental diff.

Stack order: Foundation → RNTester dependencies → Gradients → Native multipart bounds → Shared multipart parsing → Scroll offsets.

The RNTester podspec change is identical to the independently validated upstream fix; this fork PR inherits the foundation from the preceding layer. The results below keep their original scope and provenance; restacking is not a new test run.

Declare React-NativeModulesApple and use the existing depend_on_js_engine helper so CocoaPods links the selected engine. This is independent of the proposed Kotlin Multiplatform experiment; the dependency omission also reproduces in the generated source-build graph with KMP disabled.

Changelog:

[INTERNAL] [FIXED] - Declare RNTester test pod dependencies for dynamic framework source builds.

Test Plan

• Compared CocoaPods graphs from the unchanged base and corrected podspec: the dynamic base graph omits the symbol providers; the corrected graph includes them.
• Checked the engine helper with its default/Hermes settings and JSC selection.
• Compared static-library and static-framework graphs: all 12 aggregate configurations and 30 embedded-file entries remain unchanged.
• Executed the existing RNTester test plan with the exact corrected podspec in the KMP integration checkout: 151 passed, 16 upstream skips, zero failures with dynamic frameworks. The static-library and static-framework runs also each passed 151 tests.
• The native test execution above includes the KMP experiment. The independent KMP-disabled comparison checks project generation, not a second native test run. Device and Intel simulator execution were not performed.

The change is two dependency declarations; it changes no production implementation.