chore(renovate): sync enterprise-wide Renovate configuration

[rtbhouse-security-scanning]

This PR syncs the enterprise-wide Renovate configuration files:

Files added/updated:

• .github/workflows/automated-dependency-updates.yaml - Automated dependency update workflow
• .github/renovate.json5 - Renovate configuration extending central preset
• .github/renovate-file-config.js - Renovate file configuration

Notes:

• This ensures consistent Renovate behavior across the entire enterprise.
• Changes to these files in rtbhouse-platform-engineering/renovate-scanner automatically sync to all repositories.
• The configuration extends the central preset for enterprise-wide consistency.
• Dependabot alerts remain ENABLED for security visibility, but all PR creation is disabled.
• Automated security fixes disabled via API to prevent duplicate security PRs.
• Renovate will create all dependency update PRs, including security fixes from Dependabot alerts.
• Legacy root-level renovate.json5 files are automatically removed to prevent conflicts.

Requirements: The rtbhouse-platform-engineering/renovate-scanner repository must be visible to internal/private repositories across the enterprise for this to work properly.