When there are multiple requests happening at the same time, sometimes the `htmx-request` class may not be removed

When using the same loading indicator for multiple parallel requests in htmx, there is an issue where the internal request count [here](https://github.com/bigskysoftware/htmx/blob/c247cae9bf04b5b274d3bd65937541e8224a359c/src/htmx.js#L2474) can inadvertently become negative, leading to the `htmx-request` class not being removed from the designated element(s) once all requests have completed.