BF(TST): use higher level asyncio.run instead of asyncio.get_event_loop in test_inside_async

[yarikoptic]

Initially discovered in #6803 while actually making our travis CI test against python 3.10, and then reconfirmed locally in a 3.10 venv that

(git)lena:~datalad/datalad-master[master]git
$> DATALAD_TESTS_SSH=1 python -m pytest -s -v -k test_inside_async datalad
====================================================== test session starts ======================================================
platform linux -- Python 3.10.4, pytest-7.1.2, pluggy-1.0.0 -- /home/yoh/proj/datalad/datalad-master/venvs/dev3/bin/python
cachedir: .pytest_cache
rootdir: /home/yoh/proj/datalad/datalad-master, configfile: tox.ini
plugins: fail-slow-0.2.0, cov-3.0.0
collected 1297 items / 1296 deselected / 1 selected

datalad/runner/tests/test_nonasyncrunner.py::test_inside_async FAILEDVersions: annexremote=1.6.0 boto=2.49.0 cmd:7z=16.02 cmd:annex=8.20210223 cmd:bundled-git=UNKNOWN cmd:git=2.35.1 cmd:ssh=8.4p1 cmd:system-git=2.35.1 cmd:system-ssh=8.4p1 datalad=0.16.6+256.gb52a10f13 exifread=3.0.0 humanize=4.2.3 iso8601=1.0.2 keyring=23.6.0 keyrings.alt=UNKNOWN msgpack=1.0.4 mutagen=1.45.1 patoolib=1.12 platformdirs=2.5.2 requests=2.28.1 tqdm=4.64.0
Obscure filename: str=b' |;&%b5{}\'"\xce\x94\xd0\x99\xd7\xa7\xd9\x85\xe0\xb9\x97\xe3\x81\x82 .datc ' repr=' |;&%b5{}\'"ΔЙקم๗あ .datc '
Encodings: default='utf-8' filesystem='utf-8' locale.prefered='UTF-8'
Environment: PATH='/home/yoh/proj/datalad/datalad-master/venvs/dev3/bin:/home/yoh/gocode/bin:/home/yoh/gocode/bin:/home/yoh/bin:/home/yoh/.local/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/sbin:/usr/sbin:/usr/local/sbin' LANG='en_US.UTF-8' GIT_PAGER='less --no-init --quit-if-one-screen' GIT_CONFIG_PARAMETERS="'init.defaultBranch=dl-test-branch' 'clone.defaultRemoteName=dl-test-remote'" GIT_CONFIG_GLOBAL='/home/yoh/.tmp/datalad_temp_gu801k9f/.gitconfig' GIT_ASKPASS='true'

=========================================================== FAILURES ============================================================
_______________________________________________________ test_inside_async _______________________________________________________

	def test_inside_async():
		async def main():
			runner = Runner()
			return runner.run(
				(["cmd.exe", "/c"] if on_windows else []) + ["echo", "abc"],
				StdOutCapture)

>       loop = asyncio.get_event_loop()
E       DeprecationWarning: There is no current event loop

datalad/runner/tests/test_nonasyncrunner.py:378: DeprecationWarning
======================================================= warnings summary ========================================================
venvs/dev3/lib/python3.10/site-packages/duecredit/versions.py:15
  /home/yoh/proj/datalad/datalad-master/venvs/dev3/lib/python3.10/site-packages/duecredit/versions.py:15: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives
	from distutils.version import StrictVersion, LooseVersion

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
==================================================== short test summary info ====================================================
FAILED datalad/runner/tests/test_nonasyncrunner.py::test_inside_async - DeprecationWarning: There is no current event loop
========================================= 1 failed, 1296 deselected, 1 warning in 1.96s ========================================

note that it is solely due to DeprecationWarning being issued and treated as
error, which is the problem only for the master ATM but even there we do not
test really against 3.10 (problem which #6803 is trying to address).

This fix is completely replacing use of low level get_event_loop and uses
recommended by Python docs use of run. See
https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_event_loop

So, although this fix is against maint, without it we would not fail anywhere
ATM, unless manually running/testing on master against master and using python 3.10.

[bpoldrack]

Appears to hang again (not happening on master): https://ci.appveyor.com/project/mih/datalad/builds/44094400/job/f72royuoojvswqtf

Otherwise looks plausible to me.

[yarikoptic]

Seems to hang at

datalad.core.local.tests.test_create.test_create_sub_gh3463

which is different test from modified here

edit: hm -- search for test_create_sub_gh3463 ends up with no hits, including no hits for this comment. odd

[yarikoptic]

d'oh -- it is not "hanging" - it was killed after reaching a 1h running time! uff. I requested rerun of incomplete for clarity...

[christian-monch]

Thanks for the fix. LGTM

[github-actions]

🚀 PR was released in 0.17.1 🚀