Canceling restarted requests does not work as intended

[arcaria]

From the conversation on discord (https://discord.com/channels/781145214752129095/1081743238194536458/1291430902450356285):
I noticed something while trying to add this to my worker. It seems that only requests/images that are in "waiting" can be canceled, so if any one of those goes from processing to restarted and back to processing endlessly then it can not be canceled. This can happen if the request has "is_possible": true
Managed to make my worker pseudo-crash, it didn't stop the execution like I wanted, but the processes crashed
The problem was that on restarting it, it would go on to pick that request again, even though I tried VERY hard to cancel it in https://aihorde.net/api/ with the delete endpoint /v2/generate/status/{id}, but it didn't work, the request could only be canceled when I stopped my worker completely and "is_possible" changed to false

quoting db0:
"Actually, any request will be cancelled. Cancelling a request sets its n to 0. However you're right that failing a cancelled request is an edgecase I hadn't considered as a reported fault on the horde does an n += 1. But theoretically should abort after 3 retries. Need to double-check that logic. If you can open an issue I'll follow-up"