Disable push notifications when logging out of instance

[nolanlawson]

As far as I can tell, we don't unsubscribe from push notifications when you log out of an instance:

pinafore/src/routes/_actions/instances.js

Lines 36 to 88 in 97e3b04

	export async function logOutOfInstance (instanceName, message) {
	message = message || formatIntl('intl.loggedOutOfInstance', { instance: instanceName })
	const {
	composeData,
	currentInstance,
	customEmoji,
	instanceInfos,
	instanceLists,
	instanceThemes,
	loggedInInstances,
	loggedInInstancesInOrder,
	verifyCredentials
	} = store.get()
	loggedInInstancesInOrder.splice(loggedInInstancesInOrder.indexOf(instanceName), 1)
	const newInstance = instanceName === currentInstance ? loggedInInstancesInOrder[0] : currentInstance
	const objectsToClear = [
	composeData,
	customEmoji,
	instanceInfos,
	instanceLists,
	instanceThemes,
	loggedInInstances,
	verifyCredentials
	]
	for (const obj of objectsToClear) {
	delete obj[instanceName]
	}
	store.set({
	composeData,
	currentInstance: newInstance,
	customEmoji,
	instanceInfos,
	instanceLists,
	instanceThemes,
	loggedInInstances,
	loggedInInstancesInOrder,
	queryInSearch: '',
	searchResults: null,
	timelineInitialized: false,
	timelinePreinitialized: false,
	verifyCredentials
	})
	store.clearTimelineDataForInstance(instanceName)
	store.clearAutosuggestDataForInstance(instanceName)
	store.save()
	const { virtualListStore } = await importVirtualListStore()
	virtualListStore.clearRealmByPrefix(currentInstance + '/') // TODO: this is a hacky way to clear the vlist cache
	toast.say(message)
	const { enableGrayscale } = store.get()
	switchToTheme(instanceThemes[newInstance], enableGrayscale)
	/* no await */ database.clearDatabaseForInstance(instanceName)
	goto('/settings/instances')
	}

I'm surprised we haven't gotten a bug about this, though, so I could be wrong. Maybe it "just works" somehow already.