[cleanup] remove now-unnecessary cell close popover check

- thanks to the moved anchor behavior, we no longer need this, and it's actually messing up other UX

src/components/datagrid/body/data_grid_cell.tsx

@@ -457,10 +457,6 @@ export class EuiDataGridCell extends Component<
             this.setState({ disableCellTabIndex: true });
           }
         }, 0);
-      // Close the cell popover if the popover was open and the user clicked the cell
-      if (this.props.popoverContext.popoverIsOpen) {
-        this.props.popoverContext.closeCellPopover();
-      }
     }
   };