Update rmcp to 0.8.5 (#6261)

Picks up https://github.com/modelcontextprotocol/rust-sdk/pull/511 which
should fix todoist and some other MCP server oauth and may further
resolve issues in https://github.com/openai/codex/issues/5045

codex-rs/Cargo.toml

@@ -162,7 +162,7 @@ ratatui = "0.29.0"
 ratatui-macros = "0.6.0"
 regex-lite = "0.1.7"
 reqwest = "0.12"
-rmcp = { version = "0.8.4", default-features = false }
+rmcp = { version = "0.8.5", default-features = false }
 schemars = "0.8.22"
 seccompiler = "0.5.0"
 sentry = "0.34.0"