`jenkins.plugins.http_request.HttpRequestStepRoundTripTest#configRoundTripGroup1` tends to time out

[basil]

Jenkins and plugins versions report

Environment

Paste the output here

What Operating System are you using (both controller, and any agents involved in the problem)?

Ubuntu 22.04 LTS x86_64

Reproduction steps

Remove the exclusion for jenkins.plugins.http_request.HttpRequestStepRoundTripTest in excludes.txt added in #1355, then run the test suite a few times.

Expected Results

The tests should reliably pass.

Actual Results

jenkins.plugins.http_request.HttpRequestStepRoundTripTest#configRoundTripGroup1 tends to time out with the thread dump showing many threads doing work in HtmlUnit.

Anything else?

Should debug this further to find the root cause and then re-enable the test.