perf: revert NewChunkedBodyWriter

[Skyenought]

What type of PR is this?

Check the PR title.

• [x] This PR title match the format: <type>(optional scope): <description>
• [x] The description of this PR title is user-oriented and clear enough for others to understand.
• [ ] Attach the PR updating the user documentation if the current PR requires user awareness at the usage level. User docs repo

(Optional) Translate the PR title into Chinese.

(Optional) More detailed description for this PR(en: English/zh: Chinese).

en: zh(optional): 取消池化 NewChunkedBodyWriter

cpu 时间出现较大差异

0.7.1 和 0.6.1 版本的 hertz 进行比较, cpu 时间相差 8 倍

性能出现劣化

=======================================================
 hertz 0.6.1
=======================================================
Running 1m test @ http://localhost:3000/sse
  8 threads and 512 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    23.68ms   17.15ms 307.82ms   83.41%
    Req/Sec     1.86k     1.01k    4.68k    60.13%
  Latency Distribution
     50%   19.53ms
     75%   28.76ms
     90%   42.53ms
     99%   88.00ms
  776720 requests in 1.00m, 705.20MB read
  Socket errors: connect 212, read 0, write 0, timeout 0
Requests/sec:  12923.79
Transfer/sec:     11.73MB

=======================================================
 hertz 0.7.1
=======================================================

Running 1m test @ http://localhost:3000/sse
  8 threads and 512 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    29.03ms   21.50ms 312.42ms   79.90%
    Req/Sec     1.76k   816.53     4.57k    65.35%
  Latency Distribution
     50%   23.47ms
     75%   37.21ms
     90%   55.44ms
     99%  109.00ms
  630186 requests in 1.00m, 572.16MB read
  Socket errors: connect 212, read 0, write 0, timeout 0
Requests/sec:  10488.32
Transfer/sec:      9.52MB

从上面的 wrk 压测结果看出, 0.7.1 版本的 hertz 的各项指标均出现劣化

runtime.SetFinalizer 使用的并不恰当

添加 runtime.SetFinalizer 的原意是用于兜底回收, 但实际上带来了性能劣化

https://lemire.me/blog/2023/05/19/the-absurd-cost-of-finalizers-in-go/

在上面的博客中谈到, 使用 finalizer 会显著增加对象的创建和销毁的时间，大约是不使用 finalizer 的 430 倍。他建议避免使用 finalizer，除非有非常强烈的理由

(Optional) Which issue(s) this PR fixes:

(Optional) The PR that updates user documentation: