fix redis import to be explicit

lib/db.ts

@@ -1,10 +1,12 @@
 import Keyv from 'keyv'
+import KeyvRedis from '@keyv/redis'
 
 import { isRedisEnabled, redisUrl, redisNamespace } from './config'
 
 let db: Keyv
 if (isRedisEnabled) {
-  db = new Keyv(redisUrl, { namespace: redisNamespace || undefined })
+  const keyvRedis = new KeyvRedis(redisUrl)
+  db = new Keyv({ store: keyvRedis, namespace: redisNamespace || undefined })
 } else {
   db = new Keyv()
 }