loading-states extension ignores path filter on htmx:beforeOnLoad when multiple requests are in flight

[rekado]

The loading-states extension queues up callbacks on htmx:beforeRequest. On htmx:beforeOnLoad it executes any undo callbacks that mayProcessUndoCallback allows. mayProcessUndoCallback only checks for the existence of the target.

Suppose we have multiple requests in flight. We use data-loading-path to only have matching requests modify the loading states of target elements. While attaching loading states can be filtered, removing loading states always succeeds as the undo queue is drained on htmx:beforeOnLoad.

This means that target elements are marked as loaded even though their requests are still in flight.