bpo-44854: Add .editorconfig file to help enforce make patchcheck

[ambv]

https://bugs.python.org/issue44854

[1st1]

I've been a huge fan of editorconfig and considered adding one to Lib/asyncio anyways.

[pablogsal]

LGTM

[willingc]

Thanks @ambv. Makes sense.

[miss-islington]

Thanks @ambv for the PR 🌮🎉.. I'm working now to backport this PR to: 3.10.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

[miss-islington]

Thanks @ambv for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8.
🐍🍒⛏🤖

[miss-islington]

Thanks @ambv for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8, 3.9, 3.10.
🐍🍒⛏🤖

[miss-islington]

Thanks @ambv for the PR 🌮🎉.. I'm working now to backport this PR to: 3.9.
🐍🍒⛏🤖

[bedevere-bot]

GH-27712 is a backport of this pull request to the 3.10 branch.

[bedevere-bot]

GH-27714 is a backport of this pull request to the 3.9 branch.

[bedevere-bot]

GH-27713 is a backport of this pull request to the 3.8 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot PPC64LE RHEL8 LTO + PGO 3.10 has failed when building commit a6808c6.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/668/builds/245) and take a look at the build logs.
4. Check if the failure is related to this commit (a6808c6) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/668/builds/245

Summary of the results of the build (if available):

== Tests result: ENV CHANGED ==

412 tests OK.

10 slowest tests:

• test_concurrent_futures: 3 min 2 sec
• test_multiprocessing_spawn: 1 min 23 sec
• test_nntplib: 1 min 3 sec
• test_tokenize: 1 min 1 sec
• test_multiprocessing_forkserver: 58.9 sec
• test_multiprocessing_fork: 58.4 sec
• test_asyncio: 54.5 sec
• test_unparse: 50.9 sec
• test_io: 49.6 sec
• test_lib2to3: 48.3 sec

1 test altered the execution environment:
test_asyncio

14 tests skipped:
test_devpoll test_gdb test_ioctl test_kqueue test_msilib
test_ossaudiodev test_startfile test_tix test_tk test_ttk_guionly
test_winconsoleio test_winreg test_winsound test_zipfile64

Total duration: 3 min 36 sec

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/sslproto.py", line 321, in __del__
    self.close()
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/sslproto.py", line 316, in close
    self._ssl_protocol._start_shutdown()
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/sslproto.py", line 590, in _start_shutdown
    self._abort()
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/sslproto.py", line 731, in _abort
    self._transport.abort()
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/selector_events.py", line 680, in abort
    self._force_close(None)
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/selector_events.py", line 731, in _force_close
    self._loop.call_soon(self._call_connection_lost, exc)
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/base_events.py", line 745, in call_soon
    self._check_closed()
  File "/home/buildbot/buildarea/3.10.cstratak-RHEL8-ppc64le.lto-pgo/build/Lib/asyncio/base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed