Remove previous cache logic (#7794)

* Remove previous cache logic

* Remove old test

packages/next-server/lib/utils.ts

@@ -237,18 +237,6 @@ export async function loadGetInitialProps<
     return props
   }
 
-  // if page component doesn't have getInitialProps
-  // set cache-control header to stale-while-revalidate
-  if (ctx.Component && !ctx.Component.getInitialProps) {
-    const customAppGetInitialProps =
-      (Component as any).origGetInitialProps &&
-      (Component as any).origGetInitialProps !== Component.getInitialProps
-
-    if (!customAppGetInitialProps && res && res.setHeader) {
-      res.setHeader('Cache-Control', 's-maxage=86400, stale-while-revalidate')
-    }
-  }
-
   if (!props) {
     const message = `"${getDisplayName(
       Component

test/integration/cache-header/pages/_app.js

-import App from 'next/app'
-
-export default class MyApp extends App {
-  static async getInitialProps () {
-    return {}
-  }
-}

test/integration/cache-header/pages/index.js

-export default () => <p>Hi 👋</p>

test/integration/cache-header/test/index.test.js

-/* eslint-env jest */
-/* global jasmine */
-import { join } from 'path'
-import {
-  findPort,
-  killApp,
-  nextBuild,
-  nextStart,
-  fetchViaHTTP
-} from 'next-test-utils'
-
-jasmine.DEFAULT_TIMEOUT_INTERVAL = 1000 * 60
-
-const appDir = join(__dirname, '..')
-let appPort
-let server
-
-describe('Cache Header', () => {
-  beforeAll(async () => {
-    await nextBuild(appDir)
-    appPort = await findPort()
-    server = await nextStart(appDir, appPort)
-  })
-  afterAll(() => killApp(server))
-
-  it('Does not set cache header with custom getInitialProps in _app', async () => {
-    const res = await fetchViaHTTP(appPort, '/')
-    expect(res.headers.get('Cache-Control')).not.toBe(
-      's-maxage=86400, stale-while-revalidate'
-    )
-  })
-})