perf(ext/http): optimize `set_response` for small responses (#20527)

This PR introduces an optimization to `set_response` to reduce the
overhead for responses with a payload size less than 64 bytes.
Performance gains are more noticeable when `is_request_compressible`
enters the slow path, ie: `-H 'Accept-Encoding: unknown'`

### Benchmarks
```js
Deno.serve({ port: 3000 }, () => new Response("hello"));
```
```
wrk -d 10s --latency -H 'Accept-Encoding: slow' http://127.0.0.1:3000
```
---
**main**
```
Running 10s test @ http://127.0.0.1:3000
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    44.72us   28.12us   3.10ms   97.95%
    Req/Sec   112.73k     8.25k  123.66k    91.09%
  2264092 requests in 10.10s, 308.77MB read
Requests/sec: 224187.08
Transfer/sec:     30.57MB
```
**this PR**
```
Running 10s test @ http://127.0.0.1:3000
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    42.91us   20.57us   2.04ms   97.36%
    Req/Sec   116.61k     7.95k  204.81k    88.56%
  2330970 requests in 10.10s, 317.89MB read
Requests/sec: 230806.32
Transfer/sec:     31.48MB
```

0 files changed, 0 insertions, 0 deletions