Bug 1910457 [wpt PR 47336] - VT: Fix a flaky test by adding the hidden div., a=testonly

Automatic update from web-platform-tests
VT: Fix a flaky test by adding the hidden div.

This test styles the hidden div to keep the animation running, but
doesn't actually add the hidden div. The patch addresses that

R=khushalsagar@chromium.org

Bug: 355127919
Change-Id: Ib3e2bb5e25471f18886ab985904953cfdc042f6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5747070
Commit-Queue: Vladimir Levin <vmpstr@chromium.org>
Reviewed-by: Khushal Sagar <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1334372}

--

wpt-commits: bacb26dccf2a63c4d1285450dd4ff623f5d1a88c
wpt-pr: 47336

testing/web-platform/tests/css/css-view-transitions/clip-path-larger-than-border-box-on-child-of-named-element.html

@@ -51,6 +51,8 @@ html::view-transition { background: lightpink; }
   <div class="child"></div>
 </div>
 
+<div class=hidden></div>
+
 <script>
 failIfNot(document.startViewTransition, "Missing document.startViewTransition");