chore: update DEPENDABOT usage on templates

[marcossevilla]

Overview

Review and update Dependabot configuration usage across all VeryGoodOpenSource templates to ensure they are correctly configured and up to date.

Dependabot config is a CI/workflow concern and belongs here in very_good_workflows for proper ownership and visibility.

Tasks

• Audit current Dependabot usage across all templates
• Update Dependabot configs to use the latest recommended patterns
• Ensure all templates have consistent Dependabot configuration
• Verify scheduled update intervals and target branches are correct

---

Migrated from VeryGoodOpenSource/_very_good_chores#99