[resultui] disable stale-while-revalidate
[resultui] disable stale-while-revalidate

This is useless when the files are served by the service worker. It can
also generate confusing network requests in the network tab.

R=bryner, gavinmak@google.com

Change-Id: I15aa0c365b70593b60b680b929fb08c968f0113a
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2944262
Auto-Submit: Weiwei Lin <968518a24f41fef00b747498600e52b792d06ae0@google.com>
Reviewed-by: Brian Ryner <388ea68edb4d8f934960c128120aee09a8f854bf@google.com>
Commit-Queue: Brian Ryner <388ea68edb4d8f934960c128120aee09a8f854bf@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go