chore: enable mypy strict mode

[gruebel]

This PR

• most of the type hint changes are pretty straight forward
• one check of the strict checks is disabled to keep this PR rather small
• changed a list-filter-lambda combo to a list comprehension, because mypy tripped on it and in general list comprehension are more performant compared to such a combo
• also enabled mypy pretty mode, which gives quite nice error outputs
  ex.

openfeature/hook/hook_support.py:52: error: Missing type parameters for generic
type "Mapping"  [type-arg]
        hints: typing.Optional[typing.Mapping] = None,
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (30f4e69) 93.83% compared to head (b833562) 93.84%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #257      +/-   ##
==========================================
+ Coverage   93.83%   93.84%   +0.01%     
==========================================
  Files          16       16              
  Lines         438      439       +1     
==========================================
+ Hits          411      412       +1     
  Misses         27       27              

Flag	Coverage Δ
unittests	93.84% <100.00%> (+0.01%)	⬆️

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[federicobond]

Awesome work! LGTM

[federicobond]

Apparently one of the lint rules for ruff conflicts with the mypy configuration:

openfeature/_backports/strenum.py:5:22: PLC0414 Import alias does not rename original package

[gruebel]

@federicobond strange I thought I ran ruff multiple times 🤔 will ignore the rule in this specific line, because there is no other way I know to make both mypy and ruff happy. I prefer mypy to be happy 😄