These are for https://www.w3.org/TR/xhtml-pubid/, which says
"Beware. This specification is no longer in active maintenance and the
HTML Working Group does not intend to maintain it further."

Per wpt.fyi, the first 3 tests are passing everywhere and the last 2
fail everywhere, so these tests don't cover any interop issue. The
first 3 also appear to be covered by the tests here:
https://wpt.fyi/html/the-xhtml-syntax/parsing-xhtml-documents/