Rename JSX files with proper .jsx extension (#23733)

app/javascript/mastodon/components/load_more.js

@@ -1,27 +0,0 @@
-import React from 'react';
-import { FormattedMessage } from 'react-intl';
-import PropTypes from 'prop-types';
-
-export default class LoadMore extends React.PureComponent {
-
-  static propTypes = {
-    onClick: PropTypes.func,
-    disabled: PropTypes.bool,
-    visible: PropTypes.bool,
-  };
-
-  static defaultProps = {
-    visible: true,
-  };
-
-  render() {
-    const { disabled, visible } = this.props;
-
-    return (
-      <button type='button' className='load-more' disabled={disabled || !visible} style={{ visibility: visible ? 'visible' : 'hidden' }} onClick={this.props.onClick}>
-        <FormattedMessage id='status.load_more' defaultMessage='Load more' />
-      </button>
-    );
-  }
-
-}