fix: import React before using jsx (#3804)

src/components/CheckboxItem.tsx

+import React from "react";
 import clsx from "clsx";
 import { checkIcon } from "./icons";
 

src/components/LibraryButton.tsx

+import React from "react";
 import clsx from "clsx";
 import { t } from "../i18n";
 import { AppState } from "../types";