refactor: use BulkSelectSource.dropdown instead of literal

Co-authored-by: Karel Hala <ch4rlien@gmail.com>

Author: raswonders

packages/module/src/BulkSelect/BulkSelect.tsx

@@ -123,7 +123,7 @@ export const BulkSelect: FC<BulkSelectProps> = ({
       ouiaId={`${ouiaId}-dropdown`}
       onSelect={(_e, value) => {
         setOpen(!isOpen);
-        onSelect?.(value as BulkSelectValue, 'dropdown');
+        onSelect?.(value as BulkSelectValue, BulkSelectSource.dropdown);
       }}
       isOpen={isOpen}
       onOpenChange={(isOpen: boolean) => setOpen(isOpen)}