Enable package_metadata_advisory_sync and dependency_scanning_on_advisory_ingestion by default

What does this MR do and why?

Enable package_metadata_advisory_sync and dependency_scanning_on_advisory_ingestion by default at the same time.

EE: true

Changelog: added

Relates to [Feature flag] Enable package_metadata_advisory... (#420146 - closed) and [Feature flag] Rollout of `dependency_scanning_... (#419550 - closed)

Screenshots or screen recordings

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Verify the feature is enabled in the GDK rails console: Feature.enabled?(:package_metadata_advisory_sync)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.