fix: disable css cache busting in production (#41392)

Continuation of #39664 The PR removes `?ts=` in the production mode.
The corresponding e2e test case is also added.

cc @shuding

packages/next/server/app-render.tsx

@@ -1184,7 +1184,9 @@ export async function renderToHTMLOrFlight(
                 ? stylesheets.map((href) => (
                     <link
                       rel="stylesheet"
-                      href={`/_next/${href}?ts=${Date.now()}`}
+                      // Add extra cache busting (DEV only) for https://github.com/vercel/next.js/issues/5860
+                      // See also https://bugs.webkit.org/show_bug.cgi?id=187726
+                      href={`/_next/${href}${dev ? `?ts=${Date.now()}` : ''}`}
                       // `Precedence` is an opt-in signal for React to handle
                       // resource loading and deduplication, etc:
                       // https://github.com/facebook/react/pull/25060

test/e2e/app-dir/index.test.ts

@@ -264,6 +264,20 @@ describe('app dir', () => {
       expect(html).toContain('hello from app/partial-match-[id]. ID is: 123')
     })
 
+    // This is a workaround to fix https://github.com/vercel/next.js/issues/5860
+    // TODO: remove this workaround when https://bugs.webkit.org/show_bug.cgi?id=187726 is fixed.
+    it('should use cache busting when loading css (dev only)', async () => {
+      const html = await renderViaHTTP(next.url, '/')
+      const $ = cheerio.load(html)
+      const links = $('link[rel=stylesheet]')
+      links.each((_, link) => {
+        const href = $(link).attr('href')
+        isDev
+          ? expect(href).toMatch(/\?ts=/)
+          : expect(href).not.toMatch(/\?ts=/)
+      })
+    })
+
     describe('rewrites', () => {
       // TODO-APP: rewrite url is broken
       it('should support rewrites on initial load', async () => {