Only sends first batch of events to Elastic Agent on Deno

I guess _Deno_ is not a supported platform but...
When running _apm-agent-nodejs_ (4.13.0) in _Deno_ (2.3.1) **I only get the transactions sent the first 10 seconds**.
When running _apm-agent-nodejs_ in _Node.js_ it works as expected.

Here is some meta code.

Before starting Deno I set (among others):
`export ELASTIC_APM_LOG_LEVEL=trace`

At the top of the file:
`import apm from "elastic-apm-node/start.js";`

I make a number of transactions in a loop as a test.
```
loop
const trans = apm.startTransaction
trans.addLabels
trans.end
```

Unfortunately I cannot get the full logs, but here is the essence of the _trace_ messages in _Node.js_ and _Deno_ where you can see the differences.

Node.js
```
_write: encode object
gzipStream "finish"
start intakeResTimer
gzipStream "end"
completePart gzipStream
intakeReq "finish"
completePart intakeReq
intakeReq "response"
intakeRes "end"
completePart intakeRes
timeline...

intake request start
_write: encode object
intakeReq "socket": unref it

```

Deno
```
_write: encode object
gzipStream "finish"
start intakeResTimer
gzipStream "end"
completePart gzipStream
intakeReq "response"
intakeRes "end"
completePart intakeRes

```

As you can see the `intakeReq "finish"`, `completePart intakeReq`, the timeline and the three last traces where the socket is unrefed are missing when running in Deno.

Any thoughts?