SpawnProcess._async_wait: allow _main_task to exit normally

Unnecessary cancellation of _main_task triggered this ResourceWarning
for the ebuild(1) fetch command, since it prevented cleanup of
BuildLogger's internal PipeLogger instance:

sys:1: ResourceWarning: unclosed file <_io.FileIO name=10 mode='rb' closefd=True>

Signed-off-by: Zac Medico <zmedico@gentoo.org>
1 file changed