Add sockct close v2

[yangrudan]

What changes were proposed in this pull request?

1. add socket close action;
2. fix request misspell.

Why are the changes needed?

1. avoid resoure leaks.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

By run unit test.

[codecov]

Codecov Report

Attention: Patch coverage is 76.08696% with 22 lines in your changes missing coverage. Please review.

Project coverage is 79.66%. Comparing base (0c18cc5) to head (3720f4c).

Files	Patch %	Lines
dlrover/python/common/multi_process.py	76.08%	22 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1168      +/-   ##
==========================================
- Coverage   79.67%   79.66%   -0.02%     
==========================================
  Files         210      210              
  Lines       18681    18709      +28     
==========================================
+ Hits        14885    14905      +20     
- Misses       3796     3804       +8     

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[yangrudan]

@workingloong How to supply exception testing?

[workingloong]

LGTM

[workingloong]

@workingloong How to supply exception testing?

You can patch the method of socket in your test cases to raise an OSError like

dlrover/dlrover/python/tests/test_elastic_training_agent.py

Lines 202 to 207 in 0c18cc5

	def _mock_rendezvous(self, *args):
	raise RendezvousOutSyncError("test")
	agent._rendezvous = _mock_rendezvous
	with self.assertRaises(TimeoutError):
	agent._initialize_workers(agent._worker_group)

[BalaBalaYi]

@yangrudan Please resolve the conflicts.