Refactor Black Duck policy check workflow to use updated action and improve scheduling

[tuxtof]

This pull request updates the Black Duck security scan workflows by consolidating scheduled scans into a single workflow, expanding trigger conditions, and switching to a new Black Duck GitHub Action. The changes streamline security scanning and ensure more comprehensive coverage for both scheduled and pull request events.

Workflow consolidation and trigger improvements:

• Removed the .github/workflows/synopsys-schedule.yaml workflow, consolidating scheduled Black Duck scans into the main .github/workflows/synopsys.yaml file.
• Updated .github/workflows/synopsys.yaml to add scheduled (cron) triggers, and expanded pull request triggers to include more event types and branches for better coverage.

Black Duck action migration and configuration updates:

• Replaced the deprecated synopsys-sig/synopsys-action with the new blackduck-inc/black-duck-security-scan GitHub Action, updating configuration keys accordingly in both full and PR scan steps.