* Pin actions with SHA, replace unmaintained, add dependabot for actions
* Update FreeBSD to version 15 for tests
* Use shared actions
* Update sign-pipelines version
adds a GitHub Actions workflow to enforce documentation requirements for pull requests, ensuring contributors acknowledge whether their changes need documentation updates or provide a link to a corresponding docs PR.
- Adds a new GitHub Actions workflow that validates documentation acknowledgement in PR descriptions
- Updates the PR template to include mandatory documentation checkboxes and URL field
- Implements validation logic to ensure exactly one documentation option is selected and verifies docs PR URLs when provided
