Bump indexmap from 1.8.2 to 1.9.1

Bumps [indexmap](https://github.com/bluss/indexmap) from 1.8.2 to 1.9.1.
- [Release notes](https://github.com/bluss/indexmap/releases)
- [Changelog](https://github.com/bluss/indexmap/blob/master/RELEASES.md)
- [Commits](indexmap-rs/indexmap@1.8.2...1.9.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.lock

@@ -32,7 +32,7 @@ directories = "4"
 anyhow = { version = "1", features = ["backtrace"] }
 serde_yaml = "0.8.24"
 clap = { version = "3.2.5", features = ["derive"] }
-indexmap = { version = "1.8.2", features = ["serde"] }
+indexmap = { version = "1.9.1", features = ["serde"] }
 serde_json = { version = "1" }
 crossbeam = "0.8"
 rand = "0.8.5"