Jetty9 instrumentation tests are flaky

[PerfectSlayer]

Test suite

test blocking of request for request body variant multipart from datadog.trace.instrumentation.jetty9.JettyContinuationHandlerTest. Marked flaky by CircleCI

Error

Condition not satisfied:

response.code() == 413
|        |      |
|        500    false
Response{protocol=http/1.1, code=500, message=Server Error, url=http://localhost:38205/body-multipart?ignore=pair}

	at datadog.trace.agent.test.base.HttpServerTest.test blocking of request for request body variant #variant(HttpServerTest.groovy:1660)

Environment

Any version of Java and JVM.

Logs

forkedTest.zip