deps(actions): bump grafana/shared-workflows/actions/cleanup-branches@cleanup-branches/v0.2.1 (#129)

Bumps [grafana/shared-workflows/actions/cleanup-branches@cleanup-branches/v0.2.1](https://github.com/grafana/shared-workflows) from 0.2.1 to 0.3.0.
- [Release notes](https://github.com/grafana/shared-workflows/releases)
- [Commits](https://github.com/grafana/shared-workflows/compare/cleanup-branches/v0.2.1...cleanup-branches/v0.3.0)

---
updated-dependencies:
- dependency-name: grafana/shared-workflows/actions/cleanup-branches@cleanup-branches/v0.2.1
  dependency-version: 0.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/cleanup-branches.yml

@@ -12,7 +12,7 @@ jobs:
       pull-requests: read
     steps:
       - uses: actions/checkout@v6
-      - uses: grafana/shared-workflows/actions/cleanup-branches@cleanup-branches/v0.2.1
+      - uses: grafana/shared-workflows/actions/cleanup-branches@cleanup-branches/v0.3.0
         with:
           dry-run: false
           max-date: "1 month ago"