Add groups to Dependabot ecosystems

[felddy]

🗣 Description

This PR adds groups to each Dependabot ecosystem. The result will the creation of fewer PRs for version updates. Each PR can now contain multiple changes per ecosystem.

💭 Motivation and context

It gets a bit overwhelming at times to have a ton of version updates opened by dependabot. Sometimes there is no resolvable way to test dependent version changes. This happened recently with the GitHub Actions artifact upload and download actions. This should help in those situations.

🧪 Testing

Worked in other repos... 🤞

✅ Pre-approval checklist

• [x] This PR has an informative and human-readable title.
• [x] Changes are limited to a single goal - eschew scope creep!
• [x] All relevant type-of-change labels have been added.
• [x] I have read the CONTRIBUTING document.
• [x] These code changes follow cisagov code standards.
• [x] All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• [x] All new and existing tests pass.