fix: delete cache post user instead of postid

Author: sikozonpc

cmd/api/posts.go

@@ -224,6 +224,6 @@ func (app *application) updatePost(ctx context.Context, post *store.Post) error
 		return err
 	}
 
-	app.cacheStorage.Users.Delete(ctx, post.ID)
+	app.cacheStorage.Users.Delete(ctx, post.UserID)
 	return nil
 }