Remove references to tooltips and directives

app/assets/javascripts/boards/components/board_column.vue

 <script>
-import { GlTooltipDirective } from '@gitlab/ui';
 import { mapGetters, mapActions } from 'vuex';
 import Sortable from 'sortablejs';
 import BoardListHeader from 'ee_else_ce/boards/components/board_list_header.vue';
@@ -18,9 +17,6 @@ export default {
     BoardListHeader,
     BoardList: gon.features?.graphqlBoardLists ? BoardListNew : BoardList,
   },
-  directives: {
-    GlTooltip: GlTooltipDirective,
-  },
   mixins: [glFeatureFlagMixin()],
   props: {
     list: {