LoggingSpanExporter should be opt-in

[breedx-splk]

With the core of the sdk moving to otel, upstream currently defaults to using the LoggingSpanExporter as the exporter. We want span logging to be disabled by default, so this shouldn't be the case in our distro.

For a few reasons, we don't yet replace the upstream exporter, but instead inject our own BatchSpanProcessor, which has its own exporter. One option, if we continue to do this, is to omit the upstream exporter with a no-op exporter (or similar).