[Fizz] Continue reporting aborted task errors after a fatal abort (#36575)

Stacked on #36574

Normally, a fatal error transitions the request to CLOSED or CLOSING,
which prevents later aborted root tasks from reporting their errors.
Errors inside Suspense boundaries can still be reported, but other
pending root tasks are hidden once the first one fatally errors.

That behavior is useful for a normal fatal render error, where
subsequent work does not need to be processed. During an abort, however,
the abort reason is already the source of failure for every unfinished
task. Treating the first root task visited during abort cleanup as the
only observable fatal error privileges arbitrary task ordering and hides
useful information about the unfinished render.

Continue logging errors for pending tasks aborted after the request has
already fatally errored, while still only failing the shell once.