405 when deleting infractions that fail to apply

[MarkKoz]

Sentry Issue: BOT-6Q

The infractions viewset doesn't support deleting infractions, but it's done here:

bot/bot/cogs/moderation/scheduler.py

Lines 173 to 180 in a1a44be

	if failed:
	log.trace(f"Deleted infraction {infraction['id']} from database because applying infraction failed.")
	try:
	await self.bot.api_client.delete(f"bot/infractions/{id_}")
	except ResponseCodeError as e:
	confirm_msg += " and failed to delete"
	log_title += " and failed to delete"
	log.error(f"Deletion of {infr_type} infraction #{id_} failed with error code {e.status}.")

This is to delete infractions when they fail to apply on the Discord side of things. Should DELETE support be added to the API or can we re-order things to not have to later delete infractions? #986 is very relevant to this.