chore: rename variables and comments

src/picker/PickerColumn.tsx

@@ -11,7 +11,7 @@ import {
   createNamespace,
 } from '../utils';
 
-// Composition
+// Composables
 import { useParent } from '@vant/use';
 import { useTouch } from '../composables/use-touch';
 import { useExpose } from '../composables/use-expose';

src/picker/index.tsx

@@ -9,7 +9,7 @@ import {
 } from '../utils';
 import { BORDER_UNSET_TOP_BOTTOM } from '../utils/constant';
 
-// Composition
+// Composables
 import { useChildren } from '@vant/use';
 import { useExpose } from '../composables/use-expose';