Reproduce for a race condition in the Node.js https module

This reproduce is a result of digging further into the issue reported in aws/aws-sdk-js-v3#6426. It is somewhat similar to https://github.com/martinslota/aws-sdk-lib-storage-race but it does not use any AWS-specific libraries and instead uses the built-in Node.js https module directly.

Overall, it shows that HTTPS client requests tend to hang when all of the following occurs at the same time:

1. The client specifies the Expect: 100-continue header to the server.
2. The client specifies that the payload is empty using the Content-Length: 0 header to the server.
3. The client delays calling req.end() a little bit after creating the request.
4. The client calls req.end() with an empty buffer as the first argument.

These conditions are not merely theoretical: The requests sent by the AWS SDK (e.g. PutObject requests to S3) are sometimes exactly like that.

The code in index.js starts a simple HTTPS server and then hammers it, one request at a time, with requests that satisfy the above conditions.

Steps to reproduce the race condition

1. Clone this repository
2. Switch to Node.js version 22.20.0 using fnm use
3. Install dependencies using npm ci
4. Run npm start

After some time, the script tends to lock up and fail while waiting for a response, producing this kind of output.