Compatibility with pytest >=8

[BeyondEvil]

          After some more fiddling, the incompatibility might come from pytest-metadata and pytest... it seems pytest-metadata doesn't support pytest >= 8.0.0 yet, and that makes the report generation fail for some reason.

Originally posted by @supermete in pytest-dev/pytest-html#809 (comment)

[supermete]

@BeyondEvil turns out that the issue came from how I inserted data in pytest_html_results_table_html.
With previous versions, I was using py.xml.html to insert a table in data like this:

def pytest_html_results_table_html(report, data):
    data.insert(0, html.table( ... ))

That used to work but now it's not, it expects a string instead. Converting html.table into a string gets rid of the error.

I still can't have a proper report though. The only result I'm getting is an empty table with a green button saying that "There are still tests running". While I can clearly see in the stdout that the tests are finished.

Sorry I hadn't see that you created this ticket to follow-up on this. I opened a separate ticket for the issue I'm having now: pytest-dev/pytest-html#810