build(deps): bump indexmap from 1.9.3 to 2.9.0

Bumps [indexmap](https://github.com/indexmap-rs/indexmap) from 1.9.3 to 2.9.0.
- [Changelog](https://github.com/indexmap-rs/indexmap/blob/main/RELEASES.md)
- [Commits](indexmap-rs/indexmap@1.9.3...2.9.0)

---
updated-dependencies:
- dependency-name: indexmap
  dependency-version: 2.9.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

Cargo.lock

@@ -72,7 +72,7 @@ stellar-xdr = { workspace = true }
 rust-embed = { version = "8.2.0", features = ["debug-embed"] }
 regex = "1.10.5"
 toml_edit = "0.22.16"
-indexmap = { version = "1.9", features = ["serde"] }
+indexmap = { version = "2.9", features = ["serde"] }
 tempfile = "3.8"
 fs_extra = "1.3"
 webbrowser = "1.0.4"