Xcode sandbox error when building for iOS

When building the Flutter app for iOS, you may come across this error:

• error while build iOS app in Xcode : Sandbox: rsync.samba (13105) deny(1) file-write-create, Flutter failed to write to a file

To fix this:

• Open the project in Xcode and go to the build settings
• Select "all" and type "sandbox" in the search filter
• Set the "User Script Sandboxing" value to No