It appears one of these two is the one serving your audio device. Perhaps you tried both? Note the high number of interrupts on one core. So you want either irq 124 or 125.
All of your usb devices are here in order with 124 being the highest. That would suggest, as you are still having trouble, that 124 is not the one you want. (not sure yet).
You will of course need a reboot for each change. You can try replacing the 125 with any of the other 124 - 129 but as only 124 and 125 actually have interrupts showing from cat /proc/interrupts I would expect one of those two is your sound card.
It shows 4 threads, is that 4 cores or two cores with hyperthread? When I still had a machine with hyperthreading, I had to turn it off for latencies less than about 128 to have no xruns. The only other big irq user looks like your i915 (graphics I would guess) but that shouldn’t be a problem in my experience… not that my experience is great and wide, I have only used 3 or 4 cpus/gpus so not a lot.
Last time I tried this, anything that already had raised priority was not moved (lowered) to make room for a new high priority item. Maybe this has changed and in my case I had to do that for something that was not “ready” when rtirq ran at boot and so reran it. The outcome was not as expected.
That explains why trying to explicitly move the USB Port you want higher does not work. Compare that xhci listing in /proc/interrupts with one from a USB2 controller posted by Peter Hedlund:
The EHCI and UHCI entries include the port number in the IRQ listing. I do not know why the XHCI driver does not do that.