refactor!: update MSCB to not use combo-box extension internally (#9804)

Author: web-padawan

packages/combo-box/src/vaadin-combo-box-base-mixin.js

@@ -241,14 +241,13 @@ export const ComboBoxBaseMixin = (superClass) =>
 
     /**
      * Create and initialize the scroller element.
-     * Override to provide custom host reference.
      *
-     * @protected
+     * @private
      */
-    _initScroller(host) {
+    _initScroller() {
       const scroller = document.createElement(`${this._tagNamePrefix}-scroller`);
 
-      scroller.owner = host || this;
+      scroller.owner = this;
       scroller.getItemLabel = this._getItemLabel.bind(this);
       scroller.addEventListener('selection-changed', this._boundOverlaySelectedItemChanged);
 

packages/multi-select-combo-box/src/styles/vaadin-multi-select-combo-box-core-styles.js

@@ -12,6 +12,10 @@ export const multiSelectComboBoxStyles = css`
     --_chip-min-width: var(--vaadin-multi-select-combo-box-chip-min-width, 50px);
   }
 
+  :host([opened]) {
+    pointer-events: auto;
+  }
+
   #chips {
     display: flex;
     align-items: center;