[CT-3178] Scheduled dbt-extractor Builds

The external dbt-extractor package, written in rust, supports efficient "static parsing" operations in dbt-core. However, it is release very infrequently and the build procedure tends to bit-rot between releases. To make release effort more predictable, should regularly test the build process to ensure it works.

Despite the fact that this case will require changes to the dbt-labs/dbt-extractor repo, I'm filing the case against dbt-core for simpler tracking.

### Acceptance criteria

- The dbt-extractor repo is built once per week
- Build failures are reported to the #dev-core-alerts channel in slack, for follow-up by the on-call Core engineer

### Impact to Other Teams

None.

### Will backports be required?

No.

### Context

_No response_