feat(couples): wire pruneDeadTokens into onCoupleLeave

functions/src/couples/onCoupleLeave.ts

@@ -1,5 +1,6 @@
 import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'
+import { pruneDeadTokens } from '../notifications/pruneTokens'
 
 /**
  * Firestore trigger that notifies the remaining partner when a user's coupleId
@@ -125,6 +126,8 @@ export const onCoupleLeave = functions.firestore
       console.error(`[onCoupleLeave] some notifications failed:`, failures)
     }
 
+    await pruneDeadTokens(db, partnerId, tokens, sendResults)
+
     console.log(
       `[onCoupleLeave] notified partner ${partnerId} that user ${userId} left couple ${previousCoupleId}`
     )