Remove pugsql

[johnbarneson]

This pull request is dependent on experts_dw having expsql.py. I don't think we can even think about merging until we test the Cx Oracle functionality.

[nihiliad]

Since we're able to roll back this transaction, we can recover from this exception. We don't need to raise. As we do elsewhere in this project, let's log an error instead, something like this:

        except Exception as e:
            connection.rollback()
            formatted_exception = loggers.format_exception(e)
            experts_etl_logger.error(
                f'exception encountered during updating pure_sync_data tables: {formatted_exception}'
            )

[johnbarneson]

I removed the raise and implemented exception error logging as noted above.