Bug 1856976 [wpt PR 42335] - Update mutation event suppression for <details name> to revised spec rules., a=testonly

Automatic update from web-platform-tests
Update mutation event suppression for <details name> to revised spec rules.

The rules for mutation event suppression for <details name> were revised
during the process of reviewing the spec PR, based on the discussion
starting at
whatwg/html#9400 (comment) .  The
updated spec says that mutation events are suppressed during the "ensure
details exclusivity by closing other elements if needed" and "ensure
details exclusivity by closing the given element if needed" algorithms.
This updates the implementation and tests to follow that rule.  (The
"handling of insertion of elements into group" test is testing the case
where the events were already suppressed.)

This also renames the test to remove "tentative" from the name, since
the spec PR is landed and the test is now (with this change) up-to-date
with the spec.

Bug: 1444057
Change-Id: I9078beeb3527f2515f6e10efbf93a94232221238
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4912273
Commit-Queue: David Baron <dbaronchromium.org>
Reviewed-by: Joey Arhar <jarharchromium.org>
Cr-Commit-Position: refs/heads/main{#1205367}

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wpt-commits: a4288b9d453a8c48078b3e93a58c86cf97ac3551
wpt-pr: 42335

UltraBlame original commit: 79aff7d6f2407a4822f16b41afa8c0eab82537b2

Author: marco-c