Fix mypy errors

[gerlero]

No description provided.

[Copilot]

Pull Request Overview

This PR fixes mypy type checking errors by updating the MethodWithDefault protocol definition and its usage. The changes simplify the generic type parameters and ensure consistency between the protocol definition and its return type annotation.

• Removed the _Self_co covariant type variable and replaced it with a standard _Self type variable
• Updated the MethodWithDefault protocol to use fewer generic parameters
• Fixed the return type annotation in the with_default function to match the updated protocol signature

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
multicollections/_typing.py	Updated MethodWithDefault protocol definition and replaced covariant _Self_co with standard _Self
multicollections/abc.py	Fixed return type annotation to match the updated MethodWithDefault protocol signature

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (986fa9a) to head (5f0fd0b).

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #84   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
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  Files            3         3           
  Lines          352       352           
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  Hits           352       352           

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