go/adbc: unify logging config with OTel config

### What feature or improvement would you like to see?

https://github.com/apache/arrow-adbc/pull/2729 adds tracing with its own configuration of log export. We should ideally sink slog logs into OTel as well when possible.

Start by reading PR 2729 and the Go ADBC logging and tracing entry points it changes, focusing on the separate slog and OTel export configuration. Determine how the configurations should be unified and verify that slog records are sent through OTel when possible, with existing logging and tracing behavior preserved.

Written by the indexing model from the issue text.