chore: rm unneeded swiftui core import

Author: russellwheatley

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Services/AuthService.swift

@@ -1,6 +1,5 @@
 @preconcurrency import FirebaseAuth
 import SwiftUI
-import SwiftUICore
 
 public protocol ExternalAuthProvider {
   var id: String { get }