[google_sign_in_ios] Pins GoogleSignIn to 7.0.0 in podspec. (#6430)

This PR temporarily pins the GoogleSignIn iOS SDK to version 7.0.0 in the darwin podspec configuration.

This'll enable our CI to keep going, until a more proper fix to `google_sign_in_ios` lands, with an update to the latest [7.1 version](https://github.com/google/GoogleSignIn-iOS/releases). See:

* https://github.com/flutter/flutter/issues/145866

For more information about the current CI failures.

## Testing

This PR should help with the tests that are currently broken in CI.

packages/google_sign_in/google_sign_in_ios/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 5.7.5
+
+* Pins GoogleSignIn to iOS SDK "7.0.0" while preparing the update to 7.1.
+
 ## 5.7.4
 
 * Improves type handling in Objective-C code.

packages/google_sign_in/google_sign_in_ios/darwin/google_sign_in_ios.podspec

@@ -15,7 +15,7 @@ Enables Google Sign-In in Flutter apps.
   s.source_files = 'Classes/**/*.{h,m}'
   s.public_header_files = 'Classes/**/*.h'
   s.module_map = 'Classes/FLTGoogleSignInPlugin.modulemap'
-  s.dependency 'GoogleSignIn', '~> 7.0'
+  s.dependency 'GoogleSignIn', '~> 7.0.0'
   s.static_framework = true
   s.ios.dependency 'Flutter'
   s.osx.dependency 'FlutterMacOS'

packages/google_sign_in/google_sign_in_ios/pubspec.yaml

@@ -2,7 +2,7 @@ name: google_sign_in_ios
 description: iOS implementation of the google_sign_in plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/google_sign_in/google_sign_in_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+google_sign_in%22
-version: 5.7.4
+version: 5.7.5
 
 environment:
   sdk: ^3.2.3