[test] Deflake custom cache handler test (#85610)

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The test page used a low revalidate time of 3 seconds. In CI, sometimes
that much time passes between the first and second request, causing the
test to fail when comparing the data values (locally reproducible with
`{ cpuThrottleRate: 20 }`). Increasing the revalidate time to 6 seconds
should make the test more robust.

Author: unstubbable

test/e2e/app-dir/use-cache-custom-handler/app/page.tsx

@@ -7,7 +7,7 @@ import React from 'react'
 async function getData() {
   'use cache'
 
-  cacheLife({ revalidate: 3 })
+  cacheLife({ revalidate: 6 })
   cacheTag('modern')
 
   return new Date().toISOString()

test/e2e/app-dir/use-cache-custom-handler/use-cache-custom-handler.test.ts

@@ -58,12 +58,16 @@ describe('use-cache-custom-handler', () => {
     // Because we use a low `revalidate` value for the "use cache" function, new
     // data should be returned eventually.
 
-    await retry(async () => {
-      await browser.refresh()
-      data = await browser.elementById('data').text()
-      expect(data).toMatch(isoDateRegExp)
-      expect(data).not.toEqual(initialData)
-    }, 5000)
+    await retry(
+      async () => {
+        await browser.refresh()
+        data = await browser.elementById('data').text()
+        expect(data).toMatch(isoDateRegExp)
+        expect(data).not.toEqual(initialData)
+      },
+      10_000,
+      2_000
+    )
   })
 
   it('calls neither refreshTags nor getExpiration if "use cache" is not used', async () => {