refactor: remove chart import from Lit based chart-series (#9144)

Author: web-padawan

packages/charts/src/vaadin-lit-chart-series.js

@@ -8,7 +8,6 @@
  * See https://vaadin.com/commercial-license-and-service-terms for the full
  * license.
  */
-import './vaadin-lit-chart.js';
 import { LitElement } from 'lit';
 import { defineCustomElement } from '@vaadin/component-base/src/define.js';
 import { PolylitMixin } from '@vaadin/component-base/src/polylit-mixin.js';