public async Task DeleteForum(string forumId)
{
var posts = forumDbContext.Posts.Where(p => p.ForumId == forumId);
forumDbContext.RemoveRange(posts);
var threads = forumDbContext.Threads.Where(t => t.ForumId == forumId);
forumDbContext.RemoveRange(threads);
var forum = forumDbContext.Forums.Where(f => f.ForumId == forumId);
forumDbContext.RemoveRange(forum);
await forumDbContext.SaveChangesAsync();
}