Revert "Merge pull request #12416 from ahocevar/eventtype-generics"

This reverts commit b6c143deb2, reversing
changes made to 7777821df5.

src/ol/layer/BaseTile.js

@@ -45,7 +45,7 @@ import {assign} from '../obj.js';
  * options means that `title` is observable, and has get/set accessors.
  *
  * @template {import("../source/Tile.js").default} TileSourceType
- * @extends Layer<TileSourceType,'preload'|'useInterimTilesOnError'>
+ * @extends {Layer<TileSourceType>}
  * @api
  */
 class BaseTileLayer extends Layer {