tests/e2e: increase delay before snapshot

Increasing the delay before snapshots to prevent a failure in
the database-sql-driver when the nav takes too long to focus
on the current identifier.

Change-Id: If009f90c72c2f516d656f1a4ec3f55f8db9577f3
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/348935
Trust: Jamal Carvalho <jamal@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/tests/e2e/helpers/unit.page.ts b/tests/e2e/helpers/unit.page.ts
index 9466e45..c9f343c 100644
--- a/tests/e2e/helpers/unit.page.ts
+++ b/tests/e2e/helpers/unit.page.ts
@@ -24,5 +24,5 @@
     pg.$eval(page, '.go-Header', el => ((el as HTMLElement).style.visibility = 'hidden')),
     pg.$eval(page, '.go-Footer', el => ((el as HTMLElement).style.visibility = 'hidden')),
   ]);
-  await page.evaluate(() => new Promise(r => setTimeout(r, 250)));
+  await page.evaluate(() => new Promise(r => setTimeout(r, 500)));
 }