Bump indexmap from 2.7.1 to 2.8.0

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]>

Author: dependabot[bot]

Cargo.lock

@@ -16,7 +16,7 @@ readme = "README.md"
 cssparser = "0.34.0"
 ego-tree = "0.10.0"
 html5ever = "0.29.0"
-indexmap = { version = "2.7.1", optional = true }
+indexmap = { version = "2.8.0", optional = true }
 precomputed-hash = "0.1.1"
 selectors = "0.26.0"
 serde = { version = "1.0.218", optional = true }