Remove unnecessary error message when cocopods is not available (#13241)

* Remove unnecessary error message

* Add AUTHOR
diff --git a/AUTHORS b/AUTHORS
index 0b099f7..d7e59a9 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -17,3 +17,4 @@
 Mike Hoolehan <mike@hoolehan.com>
 German Saprykin <saprykin.h@gmail.com>
 Stefano Rodriguez <hlsroddy@gmail.com>
+Yusuke Konishi <yahpeycoy0403@gmail.com>
diff --git a/packages/flutter_tools/lib/src/ios/cocoapods.dart b/packages/flutter_tools/lib/src/ios/cocoapods.dart
index 8fba49d..78fd425 100644
--- a/packages/flutter_tools/lib/src/ios/cocoapods.dart
+++ b/packages/flutter_tools/lib/src/ios/cocoapods.dart
@@ -66,8 +66,6 @@
       } // TODO(xster): Add more logic for handling merge conflicts.
 
       await _runPodInstall(appIosDir, iosEngineDir);
-    } else {
-      throwToolExit('CocoaPods not available for project using Flutter plugins');
     }
   }