Removing DOM element using SSE does not close the SSE connection

In the following example, I'm trying to delete `#foo` so that the SSE connection will close.

```html

If I delete the div in developer tools (Chromium 121.0.6167.184) or using `document.getElementById("panel").innerHTML=''`, the SSE connection stays open and never seems to close.

I'm using htmx 1.9.12.

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What I'm actually trying to do is replace `#foo` with another SSE connection. But since browsers are limited to ~6 open connections at a time, I'm trying to close the existing connection before replacing it, so something like this:

```html

```

In this case the contents of `#panel` are cleared, but the browser developer tools show that the SSE connection is still open. This sometimes prevents the GET request to `/bar` if there are too many existing open connections, since the SSE connection hasn't closed.