remove this after process group destroy supported

[todo]

bagua/tests/contrib/test_fused_optimizer.py

Lines 132 to 137 in 5add7f8

	# TODO: remove this after process group destroy supported
	if not bagua.communication.is_initialized():
	bagua.init_process_group()
	def run(opt, flag_param, device, num_epochs):

---

This issue was generated by todo based on a TODO comment in 5add7f8 when #207 was merged. cc @BaguaSys.