blink: removes <img> from html fast-path

Image elements attempt to load the resource when the attributes are
set. This may have a bunch of side effects (network connections,
caching, removing preload...). Because of this, this patch removes
support for <img> from the fast path for the time being.

Bug: 1407201

Change-Id: I36ddfbd3bc688fc2a744e803a5c5de543a3d5d03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4174142
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Mason Freed <masonf@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1093858}