Fixed clang-tidy warnings

include/spdlog/details/thread_pool.h

@@ -146,6 +146,9 @@ public:
         }
     }
 
+    thread_pool(const thread_pool&) = delete;
+    thread_pool &operator=(thread_pool &&) = delete ;
+
     void post_log(async_logger_ptr &&worker_ptr, const details::log_msg &msg, async_overflow_policy overflow_policy)
     {
         async_msg async_m(std::forward<async_logger_ptr>(worker_ptr), async_msg_type::log, msg);