test: mark test-http2-reset-flood flaky on bsd

This test is somewhat regularly flaky on 12.x and it appears master as
well. There appears to be an issue tracking flakes for 6+ months. Seems
reasonable to mark this to keep us from having red CI.

Refs: https://github.com/nodejs/node/issues/29802

PR-URL: https://github.com/nodejs/node/pull/32595


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>