chore(deps): update darling requirement from 0.21 to 0.23 (modelcontextprotocol#574)

Updates the requirements on [darling](https://github.com/TedDriggs/darling) to permit the latest version.
- [Release notes](https://github.com/TedDriggs/darling/releases)
- [Changelog](https://github.com/TedDriggs/darling/blob/master/CHANGELOG.md)
- [Commits](TedDriggs/darling@v0.21.0...v0.23.0)

---
updated-dependencies:
- dependency-name: darling
  dependency-version: 0.23.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: jokemanfire <hu.dingyang@zte.com.cn>

Author: 2 people

crates/rmcp-macros/Cargo.toml

@@ -19,7 +19,7 @@ syn = {version = "2", features = ["full"]}
 quote = "1"
 proc-macro2 = "1"
 serde_json = "1.0"
-darling = { version = "0.21" }
+darling = { version = "0.23" }
 
 [features]
 [dev-dependencies]