Fix a type error

packages/lib/src/LRUCache.ts

@@ -50,7 +50,7 @@ export function cached<T, V, Args extends any[]>({
       cache.set(k, getValue(args))
     }
 
-    return cache.get(k)
+    return cache.get(k)!
   }
 
   get.cache = cache

packages/util/src/Events.ts

@@ -103,10 +103,12 @@ export const hasValidSignature = cached<string, boolean, [SignedEvent]>({
   },
   getValue: ([e]: [SignedEvent]) => {
     try {
-      return verifyEvent(e)
+      verifyEvent(e)
     } catch (err) {
       return false
     }
+
+    return true
   },
 })