Bump indexmap from 2.7.1 to 2.8.0 (#2559)

Bumps [indexmap](https://github.com/indexmap-rs/indexmap) from 2.7.1 to 2.8.0.
- [Changelog](https://github.com/indexmap-rs/indexmap/blob/main/RELEASES.md)
- [Commits](indexmap-rs/indexmap@2.7.1...2.8.0)

---
updated-dependencies:
- dependency-name: indexmap
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]