Three call sites (captureFleetdLogs at :55) attached a ListAppender to the
Fleetd.class logger with addAppender and never detached it, and never
called appender.setContext(...) either. Logback Logger instances are
cached per class and shared for the whole JVM, and surefire reuses forks,
so all three appenders stayed attached for every later test in the fork.
Convert all three call sites to CapturedLog.of(Fleetd.class) (added in
#533) via try-with-resources, which detaches the appender and sets the
context for free. Delete captureFleetdLogs(); nothing calls it now.