build: Bump serde_json from 1.0.89 to 1.0.91 in /fuzz

Bumps [serde_json](https://github.com/serde-rs/json) from 1.0.89 to 1.0.91.
- [Release notes](https://github.com/serde-rs/json/releases)
- [Commits](https://github.com/serde-rs/json/compare/v1.0.89...v1.0.91)

---
updated-dependencies:
- dependency-name: serde_json
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

fuzz/Cargo.lock

@@ -728,9 +728,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.89"
+version = "1.0.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "020ff22c755c2ed3f8cf162dbb41a7268d934702f3ed3631656ea597e08fc3db"
+checksum = "877c235533714907a8c2464236f5c4b2a17262ef1bd71f38f35ea592c8da6883"
 dependencies = [
  "itoa",
  "ryu",