fix: resolve high CPU busy-loop in event loop

[TakenCC]

This pull request resolves a high CPU busy-loop condition in hyprsunset's Wayland event loop.

Cause

When wl_display_prepare_read() fails (returns -1, e.g. due to pending events in the queue), preparedToRead is set to false. In this case, pollThread skips calling poll() but still triggers a wakeup to the event loop thread (shouldProcess = true).
However, the event loop thread only calls wl_display_dispatch_pending() if pollfds[0].revents & POLLIN is set. Since poll() was skipped, pollfds[0].revents is not updated and does not have the POLLIN flag set. As a result, the pending events are never dispatched, wl_display_prepare_read() continues to fail, and the program enters an infinite tight loop consuming 100% CPU.

Fix

Introduce a synchronized boolean wlEventsPending which is set to true whenever wl_display_prepare_read() fails (meaning events are ready to be dispatched) or pollfds[0].revents & POLLIN is set. The main loop checks this flag to determine when to call wl_display_dispatch_pending() and wl_display_flush().

[vaxerski]

tnx