Update rmcp requirement from 0.8.5 to 0.9.1

Updates the requirements on [rmcp](https://github.com/modelcontextprotocol/rust-sdk) to permit the latest version.
- [Release notes](https://github.com/modelcontextprotocol/rust-sdk/releases)
- [Commits](modelcontextprotocol/rust-sdk@rmcp-v0.8.5...rmcp-v0.9.1)

---
updated-dependencies:
- dependency-name: rmcp
  dependency-version: 0.9.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -12,7 +12,7 @@ serde_json = "1.0"
 anyhow = "1.0"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", default-features = false, features = ["env-filter", "fmt"] }
-rmcp = { version = "0.8.5", features = ["transport-streamable-http-server"] }
+rmcp = { version = "0.9.1", features = ["transport-streamable-http-server"] }
 axum = "0.8.6"
 tower = "0.5.2"
 tower-http = "0.6.6"