cargo: bump indexmap from 1.9.3 to 2.0.0

Bumps [indexmap](https://github.com/bluss/indexmap) from 1.9.3 to 2.0.0.
- [Changelog](https://github.com/bluss/indexmap/blob/master/RELEASES.md)
- [Commits](https://github.com/bluss/indexmap/compare/1.9.3...2.0.0)

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

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

Cargo.lock

@@ -883,7 +883,7 @@ dependencies = [
  "git2",
  "glob",
  "hex",
- "indexmap 1.9.3",
+ "indexmap 2.0.0",
  "insta",
  "itertools 0.11.0",
  "jujutsu-lib",

Cargo.toml

@@ -45,7 +45,7 @@ esl01-renderdag = "0.3.0"
 git2 = "0.17.2"
 glob = "0.3.1"
 hex = "0.4.3"
-indexmap = "1.9.3"
+indexmap = "2.0.0"
 itertools = "0.11.0"
 jujutsu-lib = { version = "=0.7.0", path = "lib", default-features = false }
 maplit = "1.0.2"