Bump indexmap from 1.7.0 to 1.8.0 (#3335)

Bumps [indexmap](https://github.com/bluss/indexmap) from 1.7.0 to 1.8.0.
- [Release notes](https://github.com/bluss/indexmap/releases)
- [Changelog](https://github.com/bluss/indexmap/blob/master/RELEASES.rst)
- [Commits](https://github.com/bluss/indexmap/compare/1.7.0...1.8.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Cargo.lock

@@ -1597,9 +1597,9 @@ checksum = "e0bd112d44d9d870a6819eb505d04dd92b5e4d94bb8c304924a0872ae7016fb5"
 
 [[package]]
 name = "indexmap"
-version = "1.7.0"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc633605454125dec4b66843673f01c7df2b89479b32e0ed634e43a91cff62a5"
+checksum = "282a6247722caba404c065016bbfa522806e51714c34f5dfc3e4a3a46fcb4223"
 dependencies = [
  "autocfg",
  "hashbrown",

zebrad/Cargo.toml

@@ -18,7 +18,7 @@ zebra-state = { path = "../zebra-state" }
 abscissa_core = "0.5"
 chrono = "0.4"
 gumdrop = "0.7"
-indexmap = "1.7.0"
+indexmap = "1.8.0"
 lazy_static = "1.4.0"
 serde = { version = "1", features = ["serde_derive"] }
 toml = "0.5"