fix(analytics, messaging): dedupe GoogleUtilities classes under SPM dynamic frameworks

[russellwheatley]

• Fixes [🐛] SPM + dynamic frameworks (Expo SDK 57): GoogleUtilities classes duplicated in RNFBAnalytics / RNFBMessaging #9322

RNFBAnalytics.podspec and RNFBMessaging.podspec only declared their direct Firebase SPM product (FirebaseAnalytics, FirebaseMessaging). Before this fix, GULNetwork, GULReachability, and GULMethodSwizzler ended up compiled privately into both RNFBAnalytics.framework and RNFBMessaging.framework instead of a single shared dynamic framework, so several GUL* classes were defined twice at runtime once both pods were loaded together.

Confirmed: the raw FirebaseAnalytics/GoogleAppMeasurement .xcframework binaries don't bake in copies of these classes (checked with nm), they only reference them as undefined externals like any source-based product.

Not fully confirmed: why Xcode's SPM integration fails to promote this specific cluster to a shared framework once Analytics is in the graph, when an equivalent pure-source pairing (Messaging + Auth, sharing the GULAppDelegateSwizzler cluster instead) promotes cleanly with zero private copies. It isn't simply "transitive vs explicit" either: firebase-ios-sdk's own Package.swift already lists GULNetwork/GULMethodSwizzler as explicit top-level products on FirebaseAnalyticsWrapper, in the same array as GULAppDelegateSwizzler, and only the latter shared correctly. Whether Analytics's target also carrying a binaryTarget dependency changes Xcode's per-target sharing heuristic is a live, untested hypothesis.

What's confirmed to fix it: declaring these same GoogleUtilities products as an explicit top-level spm_dependency directly on both podspecs makes Xcode build one shared dynamic framework per product and link both RNFBAnalytics and RNFBMessaging against it.

test-expo-ios-link.sh gained a check that walks every built .framework under the Expo SPM dynamic frameworks path, nm's its symbols, and fails if any of the affected GUL* classes are defined in more than one framework, or privately inside RNFBAnalytics/RNFBMessaging rather than a shared package product. Verified it fails without the podspec change and passes with it.

Also dropped the hardcoded CC=clang/LD=clang xcodebuild args in that script, they broke the pure-Swift SPM target (FirebaseCoreInternal) this repro pulls in once Analytics is added alongside Messaging.

---

Maintainer note: Fixes internal CPRN-465

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 69.83%. Comparing base (695161f) to head (9a052ab).
⚠️ Report is 19 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #9327      +/-   ##
============================================
+ Coverage     69.49%   69.83%   +0.35%     
- Complexity     2129     2130       +1     
============================================
  Files           439      439              
  Lines         25472    25518      +46     
  Branches       4251     4257       +6     
============================================
+ Hits          17700    17819     +119     
+ Misses         6365     6358       -7     
+ Partials       1407     1341      -66     

Flag	Coverage Δ
android-native	65.92% <ø> (+0.01%)	⬆️
e2e-ts-android	54.47% <ø> (+0.04%)	⬆️
e2e-ts-ios	53.89% <ø> (-0.02%)	⬇️
e2e-ts-macos	49.95% <ø> (-0.01%)	⬇️
ios-ruby	100.00% <ø> (ø)
jest	48.83% <ø> (+1.27%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.