Add clean fix for cancelation on 3.9+.

[Dreamsorcerer]

No description provided.

[codecov]

Codecov Report

Merging #235 (dbec807) into master (97161bf) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #235   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines          107       115    +8     
  Branches        16        18    +2     
=========================================
+ Hits           107       115    +8     

Flag	Coverage Δ
unit	96.52% <85.71%> (-1.61%)	⬇️

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Impacted Files	Coverage Δ
async_timeout/__init__.py	100.00% <100.00%> (ø)

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[webknjaz]

@Dreamsorcerer do you want to resurrect this effort?

[webknjaz]

Is it related to #295?

[Dreamsorcerer]

@Dreamsorcerer do you want to resurrect this effort?

I will return to this in some form, and verify if the problem is actually fixed in asyncio.timeout() or not. But, this library itself should probably be deprecated (and archived once asyncio.timeout() is available in all supported versions of Python).

Is it related to #295?

Yes, I'm pretty sure that PR is incorrect, as explained in my comments.