chore: fix all clippy warnings across workspace (#746)

examples/servers/src/common/counter.rs

@@ -1,7 +1,6 @@
 #![allow(dead_code)]
 use std::{any::Any, sync::Arc};
 
-use chrono::Utc;
 use rmcp::{
     ErrorData as McpError, RoleServer, ServerHandler,
     handler::server::{
@@ -12,14 +11,11 @@ use rmcp::{
     prompt, prompt_handler, prompt_router, schemars,
     service::RequestContext,
     task_handler,
-    task_manager::{
-        OperationDescriptor, OperationMessage, OperationProcessor, OperationResultTransport,
-    },
+    task_manager::{OperationProcessor, OperationResultTransport},
     tool, tool_handler, tool_router,
 };
 use serde_json::json;
 use tokio::sync::Mutex;
-use tracing::info;
 
 struct ToolCallOperationResult {
     id: String,