Keep two digits for the opacity value in layer state

src/ol/layer/Base.js

@@ -91,7 +91,7 @@ class BaseLayer extends BaseObject {
       layer: this,
       managed: true
     });
-    state.opacity = clamp(this.getOpacity(), 0, 1);
+    state.opacity = clamp(Math.round(this.getOpacity() * 100) / 100, 0, 1);
     state.sourceState = this.getSourceState();
     state.visible = this.getVisible();
     state.extent = this.getExtent();

src/ol/layer/Layer.js

@@ -35,7 +35,7 @@ import SourceState from '../source/State.js';
 /**
  * @typedef {Object} State
  * @property {import("./Base.js").default} layer
- * @property {number} opacity
+ * @property {number} opacity Opacity, the value is rounded to two digits to appear after the decimal point.
  * @property {SourceState} sourceState
  * @property {boolean} visible
  * @property {boolean} managed