Bump trillium-prometheus from 0.2.0 to 0.3.0 in the trillium group

Bumps the trillium group with 1 update: [trillium-prometheus](https://github.com/divviup/trillium-prometheus).


Updates `trillium-prometheus` from 0.2.0 to 0.3.0
- [Commits](https://github.com/divviup/trillium-prometheus/commits)

---
updated-dependencies:
- dependency-name: trillium-prometheus
  dependency-version: 0.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: trillium
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]