fix: Issue #12004 timegrain not visibile (#12258)

* Fix hidden dropdown when overflowing

* Remove unnecessary space

* Remove unused var

superset-frontend/src/explore/components/controls/SelectControl.jsx

@@ -225,7 +225,6 @@ export default class SelectControl extends React.PureComponent {
       filterOption,
       isLoading,
       menuPlacement,
-      menuPortalTarget,
       menuPosition,
       name,
       noResultsText,
@@ -249,7 +248,7 @@ export default class SelectControl extends React.PureComponent {
       isMulti,
       labelKey: 'label',
       menuPlacement,
-      menuPortalTarget,
+      menuPortalTarget: document.body,
       menuPosition,
       name: `select-${name}`,
       noResultsText,