Setting attribute locale={"en-US"} throws 391-395 console warnings

[n-glaz]

Describe the bug
Setting ReactDatePicker's locale attribute to 'en-US' or "en-US" causes 395 warnings to be thrown in the console when the datepicker is interacted with.

Dates still appear to be displayed properly as per the locale.

To Reproduce

import ReactDatePicker from "react-datepicker";

export const PageWithDatepicker = () => {
    <>
        <ReactDatePicker
            locale={'en-US'}
            placeholderText="Select date"
         />
    </>
}

Expected behavior

I expect to not get 395 console errors when setting the locale attribute to 'en-US'.

Screenshots

Desktop (please complete the following information):

• OS: macOS 12.5.1
• Browser: Chrome 105
• Version: "react-datepicker": "^4.8.0"

[fedemp]

According to the README, you have to import the corresponding locales from date-fns.

import { useState } from "react";
import { createRoot } from "react-dom/client";
import DatePicker, { registerLocale } from "react-datepicker";
import es from 'date-fns/locale/en-US';
registerLocale('en-US', es)
import "react-datepicker/dist/react-datepicker.css";

// CSS Modules, react-datepicker-cssmodules.css
// import 'react-datepicker/dist/react-datepicker-cssmodules.css';

const Example = (): JSX.Element => {
  const [startDate, setStartDate] = useState(new Date());
  return (
    <DatePicker
      locale="en-US"
      selected={startDate}
      onChange={(date) => date && setStartDate(date)}
    />
  );
};

const container = document.querySelector("#app")!;
const root = createRoot(container);

root.render(<Example />);