Code cleanup, remove dead code and fix compilation issue

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/core/RoomId.kt

@@ -20,5 +20,3 @@ value class RoomId(val value: String) : Serializable {
 
     override fun toString(): String = value
 }
-
-fun RoomId.toSpaceId(): SpaceId = SpaceId(this.value)

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/spaces/SpaceRoomList.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023, 2024 New Vector Ltd.
+ * Copyright 2025 New Vector Ltd.
  *
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
  * Please see LICENSE files in the repository root for full details.
@@ -22,4 +22,3 @@ interface SpaceRoomList {
     val paginationStatusFlow: StateFlow<PaginationStatus>
     suspend fun paginate(): Result<Unit>
 }
-