[Feature] Bigquery job labels missing when using CopyJobConfig in copy_bq_table

[Alex-Krykun]

Is this a new bug in dbt-bigquery?

• I believe this is a new bug in dbt-bigquery
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

When DBT copies temp tables to the destination table, BQ Jobs missing labels.

Expected Behavior

Add job_labels for copying table as well as for other operations.

Steps To Reproduce

Run any dbt module that involves a copy table, and check in the BQ Console that the job doesn't have any custom labels.

Relevant log output

Please, check https://github.com/dbt-labs/dbt-bigquery/blob/main/dbt/adapters/bigquery/connections.py#L443 for CopyJobConfig we can pass labels (IMHO).

Environment

- OS:MacOS Sequoia 15.3
- Python:3.10
- dbt-core: 1.9.0
- dbt-bigquery: 1.9.0

Additional Context

No response

[Alex-Krykun]

I created a draft PR: dbt-labs/dbt-bigquery#1464, as changes included all methods that have already been covered by unit tests, I am not sure if I need to add additional checks, and if yes where exactly.

[Alex-Krykun]

As a possible solution, please, consider my PR #795
Thank you!