type: simplify getPlacement return type (#40775)

components/select/index.tsx

@@ -1,7 +1,7 @@
 // TODO: 4.0 - codemod should help to change `filterOption` to support node props.
 import classNames from 'classnames';
+import type { BaseSelectRef, SelectProps as RcSelectProps } from 'rc-select';
 import RcSelect, { OptGroup, Option } from 'rc-select';
-import type { SelectProps as RcSelectProps, BaseSelectRef } from 'rc-select';
 import type { OptionProps } from 'rc-select/lib/Option';
 import type { BaseOptionType, DefaultOptionType } from 'rc-select/lib/Select';
 import omit from 'rc-util/lib/omit';
@@ -18,10 +18,10 @@ import type { InputStatus } from '../_util/statusUtils';
 import { getMergedStatus, getStatusClassNames } from '../_util/statusUtils';
 import getIcons from './utils/iconUtil';
 
-import useStyle from './style';
+import { useCompactItemContext } from '../space/Compact';
 import genPurePanel from '../_util/PurePanel';
 import warning from '../_util/warning';
-import { useCompactItemContext } from '../space/Compact';
+import useStyle from './style';
 
 type RawValue = string | number;
 
@@ -182,13 +182,11 @@ const InternalSelect = <OptionType extends BaseOptionType | DefaultOptionType =
   );
 
   // ===================== Placement =====================
-  const getPlacement = () => {
+  const getPlacement = (): SelectCommonPlacement => {
     if (placement !== undefined) {
       return placement;
     }
-    return direction === 'rtl'
-      ? ('bottomRight' as SelectCommonPlacement)
-      : ('bottomLeft' as SelectCommonPlacement);
+    return direction === 'rtl' ? 'bottomRight' : 'bottomLeft';
   };
 
   // ====================== Warning ======================