build: Bump serde from 1.0.164 to 1.0.168

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.164 to 1.0.168.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](https://github.com/serde-rs/serde/compare/v1.0.164...v1.0.168)

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

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

virtio-devices/Cargo.toml

@@ -21,7 +21,7 @@ net_util = { path = "../net_util" }
 pci = { path = "../pci" }
 rate_limiter = { path = "../rate_limiter" }
 seccompiler = "0.3.0"
-serde = { version = "1.0.164", features = ["derive"] }
+serde = { version = "1.0.168", features = ["derive"] }
 serde_json = "1.0.96"
 serial_buffer = { path = "../serial_buffer" }
 thiserror = "1.0.40"