Corrected Colors enum under Python 3.11

[LiraNuna]

Python 3.11 have made some changes to how mixed-in Enum formatting works. From the changelog:

Changed Enum.__format__() (the default for format(), str.format() and f-strings) of enums with mixed-in types (e.g. int, str) to also include the class name in the output, not just the member’s key. This matches the existing behavior of enum.Enum.__str__(), returning e.g. 'AnEnum.MEMBER' for an enum AnEnum(str, Enum) instead of just 'MEMBER'.

This PR fixes this issue by using the new StrEnum from Python 3.11 if available, substituting it for a subclass otherwise.

NOTE: I would recommend adding python 3.11 to unit tests before merging this one.

Fixes #2589

[codecov]

Codecov Report

Base: 87.866% // Head: 87.870% // Increases project coverage by +0.004% 🎉

Coverage data is based on head (12972b7) compared to base (aef2673).
Patch coverage: 100.000% of modified lines in pull request are covered.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #2590       +/-   ##
=============================================
+ Coverage   87.866%   87.870%   +0.004%     
=============================================
  Files           71        71               
  Lines         5357      5359        +2     
  Branches       893       893               
=============================================
+ Hits          4707      4709        +2     
  Misses         471       471               
  Partials       179       179               

Impacted Files	Coverage Δ
sanic/log.py	100.000% <100.000%> (ø)

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[ahopkins]

NOTE: I would recommend adding python 3.11 to unit tests before merging this one.

Yup, that is a tomorrow task 😎 I think uvloop added 3.11, need to double check if that was released otherwise we need to wait.