`http-proxy-middleware` attempts to handle request when response has already been sent by `webpack-dev-middleware`

[mjames-c]

Bug report

http-proxy-middleware attempts to handle request when response has already been sent by webpack-dev-middleware. fixing this should be as simple as adding a check on res.headersSent to the http-proxy-middleware handler

Actual Behavior

webpack-dev-server prints the following error logs to the console:

<e> [webpack-dev-server] [HPM] ECONNRESET: Error: socket hang up
<e>     at TLSSocket.socketOnEnd (node:_http_client:528:25)
<e>     at TLSSocket.emit (node:events:530:35)
<e>     at TLSSocket.emit (node:domain:489:12)
<e>     at endReadableNT (node:internal/streams/readable:1698:12)
<e>     at processTicksAndRejections (node:internal/process/task_queues:82:21) {
<e>   code: 'ECONNRESET'
<e> }

Expected Behavior

webpack-dev-server does NOT attempt to proxy the request.

How Do We Reproduce?

// webpack.config.js
{
  devServer: {
    proxy: {
      context: () => true
    },
  }
}

Please paste the results of npx webpack-cli info here, and mention other relevant information

  System:
    OS: Linux 6.8 Ubuntu 22.04.5 LTS 22.04.5 LTS (Jammy Jellyfish)
    CPU: (16) x64 Intel(R) Xeon(R) Platinum 8375C CPU @ 2.90GHz
    Memory: 102.13 GB / 123.81 GB
  Packages:
    babel-loader: ^8.0.6 => 8.2.4 
    css-loader: ^5.2.4 => 5.2.6 
    ejs-loader: ^0.5.0 => 0.5.0 
    file-loader: ^5.0.2 => 5.0.2 
    html-webpack-plugin: ~5.5.0 => 5.5.3 
    loader-runner: ^4.1.0 => 4.2.0 
    loader-utils: ^1.2.3 => 1.2.3 
    postcss-loader: ^5.2.0 => 5.2.0 
    raw-loader: ^4.0.0 => 4.0.2 
    svg-url-loader: ^3.0.3 => 3.0.3 
    svgo-loader: ^3.0.0 => 3.0.0 
    swc-loader: ^0.2.6 => 0.2.6 
    terser-webpack-plugin: ^5.2.4 => 5.3.9 
    thread-loader: ^4.0.2 => 4.0.2 
    ts-loader: ^9.4.4 => 9.4.4 
    url-loader: ^4.1.1 => 4.1.1 
    webfontloader: ^1.6.28 => 1.6.28 
    webpack: 5.99.9 => 5.99.9 
    webpack-cli: ^5.1.4 => 5.1.4 
    webpack-dev-server: ^5.2.1 => 5.2.1 
    webpackbar: ^5.0.0-3 => 5.0.0-3