ci(swift): Fix Swift integration failure for PRs from external contributors (#17577)

* ci(swift): use GITHUB_REPOSITORY env to construct Swift package URL dynamically to handle forked repositories

* chore: print reposlug

* add env to store repository name

* add script to print PR info

* reference PR_HEAD_REPO

* reference PR_HEAD_REPO

* clean up code

* clean up code

Author: SelaseKay

.github/workflows/all_plugins.yaml

@@ -127,6 +127,7 @@ jobs:
     timeout-minutes: 30
     env:
       FLUTTER_DEPENDENCIES: "cloud_firestore firebase_remote_config cloud_functions firebase_database firebase_auth firebase_storage firebase_analytics firebase_messaging firebase_app_check firebase_in_app_messaging firebase_performance firebase_crashlytics firebase_ml_model_downloader firebase_app_installations"
+      PR_HEAD_REPO: ${{ github.event.pull_request.head.repo.full_name }}
     steps:
       - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff

.github/workflows/scripts/swift-integration.dart

@@ -81,8 +81,14 @@ Future<void> updatePackageSwiftForPackage(String packageName, String branch) asy
       multiLine: true
     );
 
+    final headRepo = Platform.environment['PR_HEAD_REPO'];
+    final baseRepo = Platform.environment['GITHUB_REPOSITORY'];
+
+    // handles forked repositories
+    final repoSlug = headRepo != baseRepo ? headRepo : baseRepo;
+
     // Replace with branch dependency
-    final branchDependency = '.package(url: "https://github.com/firebase/flutterfire", branch: "$branch")';
+    final branchDependency = '.package(url: "https://github.com/$repoSlug", branch: "$branch")';
 
     if (exactVersionPattern.hasMatch(content)) {
       updatedContent = content.replaceAll(exactVersionPattern, branchDependency);