[MM-55328] Convert './components/toggle_modal_button/toggle_modal_button.test.tsx' from Class Component to Function Component (#25523)

webapp/channels/src/components/toggle_modal_button.test.tsx

@@ -15,9 +15,7 @@ jest.mock('react-redux', () => ({
     useDispatch: () => jest.fn(),
 }));
 
-class TestModal extends React.PureComponent {
+const TestModal = () => (
-    render() {
-        return (
     <Modal
         show={true}
         onHide={jest.fn()}
@@ -26,8 +24,6 @@ class TestModal extends React.PureComponent {
         <Modal.Body/>
     </Modal>
 );
-    }
-}
 
 describe('components/ToggleModalButton', () => {
     test('component should match snapshot', () => {