message: types: improve event target typing
diff: @@ -20,7 +20,7 @@ if (!isServer) {
  }
  export function on(
  - target: HTMLElement | Document | Window,
  + target: EventTarget,
  event: string,
  handler: EventHandler,
  passive = false
  @@ -35,7 +35,7 @@ export function on(
  }
  export function off(
  - target: HTMLElement | Document | Window,
  + target: EventTarget,
  event: string,
  handler: EventHandler
  ) {
  