feat: clean test

src/components/LegalNotice/LegalNoticeLink.spec.tsx

-'use strict'
-/* eslint-env jest */
 import React from 'react'
 import { shallow } from 'enzyme'
 import LegalNoticeLink from 'components/LegalNotice/LegalNoticeLink'

src/components/LegalNotice/LegalNoticeView.spec.tsx

-'use strict'
-/* eslint-env jest */
 import React from 'react'
 import { shallow } from 'enzyme'
 import LegalNoticeView from 'components/LegalNotice/LegalNoticeView'

src/components/Navbar/Navbar.spec.tsx

-'use strict'
-/* eslint-env jest */
 import React from 'react'
 import { shallow } from 'enzyme'
 import Navbar from 'components/Navbar/Navbar'

src/components/Welcome/WelcomeModal.spec.tsx

-'use strict'
-/* eslint-env jest */
 import React from 'react'
 import { shallow } from 'enzyme'
 import WelcomeModal from './WelcomeModal'