Exported, and main calls it, specifically so the wiring can be tested. A
test that constructs its own worker would pass with this wiring deleted,
which is the failure mode that let #2790 happen: a sweep that silently never
runs looks exactly like a sweep with nothing to do.
Resolve blob-GC settings from the environment.
Exported, and
maincalls it, specifically so the wiring can be tested. A test that constructs its own worker would pass with this wiring deleted, which is the failure mode that let #2790 happen: a sweep that silently never runs looks exactly like a sweep with nothing to do.