Replace deprecated imp module with importlib

[hugovk]

This project's tests use the imp module which has been deprecated since Python 3.4 and removed in 3.12:

• Raised PendingDeprecationWarning since 3.4 (2014)
• Raised DeprecationWarning since 3.5 (2015)
• Updated DeprecationWarning to say removal in 3.12 since 3.10 (2021)
• Removal planned for 3.12 (2023)

Python 3.12 is set for release on 2023-10-02 and this library is one of the top 5,000 most-downloaded from PyPI.

Please could you upgrade to use importlib? The imp docs have suggestions on what to use to replace each function and constant.

crochet/crochet/tests/test_api.py

Lines 540 to 564 in deea55f

	imp.acquire_lock()
	lock_held.set()
	test_complete.wait()
	imp.release_lock()
	t = threading.Thread(target=other_thread)
	t.start()
	lock_held.wait()
	# While the imp lock is held by the other thread, we can't
	# allow exceptions/assertions to happen because trial will
	# try to do an import causing a deadlock instead of a
	# failure. We collect all assertion pairs (result, expected),
	# wait for the import lock to be released, and then check our
	# assertions at the end of the test.
	assertions = []
	# we want to run .wait while the other thread has the lock acquired
	assertions.append((imp.lock_held(), True))
	try:
	assertions.append((er.wait(0.1), 123))
	finally:
	test_complete.set()
	assertions.append((imp.lock_held(), True))

[itamarst]

I should probably just delete that test, I suspect it's not really necessary in modern Python.

[itamarst]

Or just switch to importing a module with a sleep that runs at import time.