Create context in the canvas layer base class

src/ol/renderer/canvas/ImageLayer.js

@@ -22,15 +22,6 @@ class CanvasImageLayerRenderer extends CanvasLayerRenderer {
   constructor(imageLayer) {
     super(imageLayer);
 
-    /**
-     * @protected
-     * @type {CanvasRenderingContext2D}
-     */
-    this.context = createCanvasContext2D();
-
-    const canvas = this.context.canvas;
-    canvas.style.position = 'absolute';
-
     /**
      * @protected
      * @type {import("../../transform.js").Transform}