Support otel metrics exporter

What feature would you like to see?

Similar to otel logs and tracing, can we support configuring metrics exporter that we can use to gather internal usage metrics of codex CLI?

Additional information

I tried the below configuration, but doesn't seem to be working:

[otel]
metrics_exporter = { otlp-grpc = {
  endpoint = "http://localhost:18234"
}}

The similar configuration works for traces and logs.