MetricsComponent runs background services and never checks on them

[gsalgado]

That component is also affected by the fire-and-forget anti pattern:

trinity/trinity/components/builtin/metrics/component.py

Lines 166 to 171 in 066e925

	async with contextlib.AsyncExitStack() as stack:
	managers = tuple([
	await stack.enter_async_context(background_trio_service(service))
	for service in services_to_exit
	])
	await managers[0].wait_finished()

That component runs until the first started service's wait_finished() returns (which can be due to a service crashing). Instead it should probably exit as soon as any of the started services wait_finished()` returns