Update serial_test requirement from 2.0.0 to 3.0.0

Updates the requirements on [serial_test](https://github.com/palfrey/serial_test) to permit the latest version.
- [Release notes](https://github.com/palfrey/serial_test/releases)
- [Commits](palfrey/serial_test@v2.0.0...v3.0.0)

---
updated-dependencies:
- dependency-name: serial_test
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

ractor/Cargo.toml

@@ -38,7 +38,7 @@ backtrace = "0.3"
 criterion = "0.5"
 function_name = "0.3"
 paste = "1"
-serial_test = "2.0.0"
+serial_test = "3.0.0"
 rand = "0.8"
 tokio = { version = "1", features = ["rt", "time", "sync", "macros", "rt-multi-thread", "tracing"] }
 tracing-glog = "0.3"