[REM] web: remove dead code: calendar filter panel

Since c959386 the calendar filter panel does not
make use of popovers.
So there is no need to call the usePopover hook
in this component's setup.

Part-of: odoo/odoo#118066

addons/web/static/src/views/calendar/filter_panel/calendar_filter_panel.js

@@ -1,6 +1,5 @@
 /** @odoo-module **/
 
-import { usePopover } from "@web/core/popover/popover_hook";
 import { _t } from "@web/core/l10n/translation";
 import { AutoComplete } from "@web/core/autocomplete/autocomplete";
 import { Transition } from "@web/core/transition";
@@ -20,7 +19,6 @@ export class CalendarFilterPanel extends Component {
         });
         this.addDialog = useOwnedDialogs();
         this.orm = useService("orm");
-        this.popover = usePopover();
     }
 
     getFilterColor(filter) {