Bug 1883520 [wpt PR 44916] - Add interestaction attribute, a=testonly

Bug 1883520 [wpt PR 44916] - Add interestaction attribute, a=testonly

Automatic update from web-platform-tests
Add interestaction attribute

This adds support for the experimental `interestaction` attribute,
as specified in the open-ui "Interest Invokers" explainer.

(https://open-ui.org/components/interest-invokers.explainer/)

The `interestaction` attribute maps to the IDL `interestAction` similar
to `invokeAction`.

This attribute currently has no behaviour changes associated with it,
that will be handled in follow-ups.

Bug: 326681249
Change-Id: I18c806476378ef7213482d339032ecd4b0a50b78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5340853
Reviewed-by: Mason Freed <masonf@chromium.org>
Commit-Queue: Luke <lwarlow@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1269261}

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wpt-commits: 4e4366f48f12531d5ea38b6beee9e528330cb200
wpt-pr: 44916