[booster] fix no_sync method

[ver217]

Overview

Booster.no_sync() calls Plugin.no_sync(), see

ColossalAI/colossalai/booster/booster.py

Line 151 in f83ea81

return self.plugin.no_sync(model)

.

However, we didn't define this method in Plugin class. We should add this method and implment this method in subclasses.

Wanna track the development progress? Take a look at

proposal: #3046
project kanban: API Refactoring

Goal

1. Add no_sync() method in Plugin class.
2. Implement this method in subclasses.