use configured stack size for threads in thread_pool

Author: brainkim

Diff for: src/thread_pool.zig

@@ -472,7 +472,7 @@ noinline fn notifySlow(self: *ThreadPool, is_waking: bool) void {
 
             // We signaled to spawn a new thread
             if (can_wake and sync.spawned < self.max_threads) {
-                const spawn_config = std.Thread.SpawnConfig{ .stack_size = default_thread_stack_size };
+                const spawn_config = std.Thread.SpawnConfig{ .stack_size = self.stack_size };
                 const thread = std.Thread.spawn(spawn_config, Thread.run, .{self}) catch return self.unregister(null);
                 // if (self.name.len > 0) thread.setName(self.name) catch {};
                 return thread.detach();