butil::get_resource<Task> 疑似内存泄漏

**Describe the bug (描述bug)**
使用BRPC框架的进程，长期运行(一个月)，可以观察到内存持续上涨，如下图：


追踪内存泄漏位置如下


**To Reproduce (复现方法)**
单进程2k左右qps， 消息请求平均大小150KB

**Expected behavior (期望行为)**
期望内存不会持续上涨

**Versions (各种版本)**
OS:
Linux 5.15.0-125.006 #125~20.04.3 SMP Fri May 24 11:59:50 +08 2024 x86_64 x86_64 x86_64 GNU/Linux

Compiler:
g++ (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

brpc:
tag 1.10.0

jemalloc 生成的内存分布图：
[3_5.pdf](https://github.com/user-attachments/files/19084719/3_5.pdf)

jemalloc 生成的内存分布占比：
[memory.txt](https://github.com/user-attachments/files/19084786/memory.txt)

Start by inspecting butil::get_resource and reproduce the reported long-running workload of about 2,000 QPS with 150 KB requests on the stated Linux and brpc 1.10.0 environment. Use the provided jemalloc PDF and memory report to compare allocation growth; done means identifying and fixing the leak so memory no longer rises continuously under sustained load.

Written by the indexing model from the issue text.