build: Bump serde from 1.0.203 to 1.0.208

Bumps [serde](https://github.com/serde-rs/serde) from 1.0.203 to 1.0.208.
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](https://github.com/serde-rs/serde/compare/v1.0.203...v1.0.208)

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

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

net_util/Cargo.toml

@@ -11,7 +11,7 @@ libc = "0.2.155"
 log = "0.4.22"
 net_gen = { path = "../net_gen" }
 rate_limiter = { path = "../rate_limiter" }
-serde = { version = "1.0.197", features = ["derive"] }
+serde = { version = "1.0.208", features = ["derive"] }
 thiserror = "1.0.62"
 virtio-bindings = "0.2.2"
 virtio-queue = "0.12.0"