Update Chrome Root Store FAQ to address QUIC

This CL updates the Chrome Root Store FAQ to make it clear that
enterprise trust is NOT considered for connections relying on HTTP/3
(QUIC).

Fixed: 398893926

Change-Id: I015e23dfb5e7569e28703c7f69792fca1c0d4399
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6328878
Reviewed-by: Matt Mueller <mattm@chromium.org>
Reviewed-by: Hubert Chao <hchao@chromium.org>
Commit-Queue: Ryan Dickson <ryandickson@google.com>
Cr-Commit-Position: refs/heads/main@{#1431498}