[issue40600] Add option to disallow > 1 instance of an extension module

[Dong-hee Na]

Change by Dong-hee Na <donghee.na at python.org>:


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pull_requests: +22566
pull_request: https://github.com/python/cpython/pull/23699

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue40600>
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