message: Replaced type of arg in removeSeries in ChartApi
  It's implementation, so we don't need to use widen types
diff: @@ -266,9 +266,8 @@ export class ChartApi implements IChartApi, IPriceScaleApiProvider, DataUpdatesC
  return res;
  }
  - public removeSeries(seriesApi: ISeriesApi<SeriesType>): void {
  - const seriesObj = seriesApi as SeriesApi<SeriesType>;
  - const series = ensureDefined(this._seriesMap.get(seriesObj));
  + public removeSeries(seriesApi: SeriesApi<SeriesType>): void {
  + const series = ensureDefined(this._seriesMap.get(seriesApi));
  const update = this._dataLayer.removeSeries(series);
  const model = this._chartWidget.model();
  @@ -279,7 +278,7 @@ export class ChartApi implements IChartApi, IPriceScaleApiProvider, DataUpdatesC
  key.updateData(value.update);
  });
  model.updateTimeScaleBaseIndex(0 as TimePointIndex);
  - this._seriesMap.delete(seriesObj);
  + this._seriesMap.delete(seriesApi);
  this._seriesMapReversed.delete(series);
  }
  