chore: group logically-related test cases in shared describe blocks (#…

…1599)

## Description

This PR resolves the max-statements warning in `capability.test.ts` by
using describe blocks.

End to End Test:  <!-- if applicable -->  
(See [Pepr Excellent
Examples](https://github.com/defenseunicorns/pepr-excellent-examples))

## Related Issue

Relates to linter warning fixes.

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Other (security config, docs update, etc)

## Checklist before merging
- [x] Unit,
[Journey](https://github.com/defenseunicorns/pepr/tree/main/journey),
[E2E Tests](https://github.com/defenseunicorns/pepr-excellent-examples),
[docs](https://github.com/defenseunicorns/pepr/tree/main/docs),
[adr](https://github.com/defenseunicorns/pepr/tree/main/adr) added or
updated as needed
- [x] [Contributor Guide
Steps](https://docs.pepr.dev/main/contribute/#submitting-a-pull-request)
followed