build: bump serde_json from 1.0.80 to 1.0.81

Bumps [serde_json](https://github.com/serde-rs/json) from 1.0.80 to 1.0.81.
- [Release notes](https://github.com/serde-rs/json/releases)
- [Commits](https://github.com/serde-rs/json/compare/v1.0.80...v1.0.81)

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

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

Cargo.toml

@@ -26,7 +26,7 @@ libc = "0.2.125"
 log = { version = "0.4.17", features = ["std"] }
 option_parser = { path = "option_parser" }
 seccompiler = "0.2.0"
-serde_json = "1.0.80"
+serde_json = "1.0.81"
 signal-hook = "0.3.13"
 thiserror = "1.0.31"
 vmm = { path = "vmm" }
@@ -46,7 +46,7 @@ versionize_derive = { git = "https://github.com/cloud-hypervisor/versionize_deri
 dirs = "4.0.0"
 lazy_static= "1.4.0"
 net_util = { path = "net_util" }
-serde_json = "1.0.80"
+serde_json = "1.0.81"
 test_infra = { path = "test_infra" }
 wait-timeout = "0.2.0"