Enable detekt rules OptionalUnit and fix existing issues.

features/invitelist/impl/src/main/kotlin/io/element/android/features/invitelist/impl/InviteListPresenter.kt

@@ -152,8 +152,7 @@ class InviteListPresenter @Inject constructor(
             client.getRoom(roomId)?.use {
                 it.leave().getOrThrow()
                 notificationDrawerManager.clearMembershipNotificationForRoom(client.sessionId, roomId)
-            }
-            Unit
+            }.let { }
         }.runCatchingUpdatingState(declinedAction)
     }
 

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/MessagesView.kt

@@ -125,8 +125,9 @@ fun MessagesView(
         state.eventSink(MessagesEvents.ToggleReaction(emoji, event.eventId))
     }
 
-    fun onMoreReactionsClicked(event: TimelineItem.Event): Unit =
+    fun onMoreReactionsClicked(event: TimelineItem.Event) {
         state.customReactionState.eventSink(CustomReactionEvents.UpdateSelectedEvent(event.eventId))
+    }
 
     Scaffold(
         modifier = modifier,