Collector exporter does not log errors when requests fail

[dashpole]

After removing retry_on_failure in open-telemetry/opentelemetry-collector-contrib#25900, we no longer get any log messages when we fail to send.

Discovered in #760.

[aabmass]

Looking at the original PR, its very weird that this removed logging. I would have expected the collector to log errors for you even without exporterhelper. Do you think there is an upstream collector bug here?

[dashpole]

Opened open-telemetry/opentelemetry-collector#8791 and open-telemetry/opentelemetry-collector#8792. We can hold off fixing it here until those are resolved.

[dashpole]

Fixed by open-telemetry/opentelemetry-collector#8792