[BOOK-169] chore: 미사용 Book 클래스 제거

Author: seoyoon513

feature/home/src/main/kotlin/com/ninecraft/booket/feature/home/HomeUiState.kt

@@ -17,11 +17,3 @@ sealed interface HomeUiEvent : CircuitUiEvent {
     data class OnRecordButtonClick(val userBookId: String) : HomeUiEvent
     data object OnBookDetailClick : HomeUiEvent
 }
-
-data class Book(
-    val title: String = "",
-    val author: String = "",
-    val publisher: String = "",
-    val imageUrl: String = "",
-    val reviewCount: Int = 0,
-)