Non-Flutter targets can use the FLUTTER_ build settings like FLUTTER_BUILD_NAME and FLUTTER_BUILD_NUMBER to keep version numbers in sync between executables. The easiest way to do that is for targets to inherit from the Debug.xcconfig and Release.xcconfig base configurations. However, #51453 introduced OTHER_LDFLAGS=$(inherited) -framework Flutter, so any target that does so would try to link on Flutter, even if the target does not use Flutter (and thus doesn't have Flutter in its search paths), or even is watchOS or tvOS.

One workaround is to conditionalize the build setting to the iOS SDK. That doesn't help with non-Flutter iOS targets, but it would mean watchOS and tvOS could use the xcconfig.

Context: #54691 (comment)

1. Change to OTHER_LDFLAGS[sdk=iphone*]=$(inherited) -framework Flutter.
2. Remove OTHER_LDFLAGS from flutter_export_environment.sh since OTHER_LDFLAGS[sdk=iphone*]` is not a valid environment variable, and host apps already link on Flutter and don't need this linker flag.