These changes allow test_dom_token_list from
/execute_script/collections.py to pass, and various tests in
/execute_script/arguments.py to expose new failures.
Testing: Not run in CI yet, but verified results from
tests/wpt/tests/webdriver/tests/classic/{execute_script,execute_async_script}
locally.
Fixes: #35738
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Signed-off-by: Josh Matthews <josh@joshmatthews.net>