build(deps): update rust-mcp-sdk requirement

Updates the requirements on [rust-mcp-sdk](https://github.com/rust-mcp-stack/rust-mcp-sdk) to permit the latest version.
- [Release notes](https://github.com/rust-mcp-stack/rust-mcp-sdk/releases)
- [Changelog](https://github.com/rust-mcp-stack/rust-mcp-sdk/blob/main/.release-config.json)
- [Commits](rust-mcp-stack/rust-mcp-sdk@rust-mcp-sdk-v0.4.3...rust-mcp-sdk-v0.6.0)

---
updated-dependencies:
- dependency-name: rust-mcp-sdk
  dependency-version: 0.6.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

rust-mcp-server-syncable-cli/Cargo.toml

@@ -27,7 +27,7 @@ categories = [
 
 [dependencies]
 async-trait = "0.1.88"
-rust-mcp-sdk = "0.4.3"
+rust-mcp-sdk = "0.6.0"
 tracing = "0.1.41"
 tracing-subscriber = { version = "0.3.19", features = ["fmt", "env-filter"] }
 serde = { version = "1.0", features = ["derive"] }