exposed.*.html tests are broken #4654

There are more problems with the test (it uses ERROR instead of fail for failure), but the most prominent problem is that if one "passes" all assertions the test will time out: https://searchfox.org/firefox-main/source/testing/web-platform/mozilla/meta/webgpu/cts/idl/exposed.http.html.ini
Also observed in servo: servo/servo#45279

We need to report that test is done somehow, although it might make more sense to just rewrite the tests with proper WPTs idlharness as said in #332