refactor(cargo_provider): cleanup and get rid of potential type errors

[bearomorphism]

Description

Checklist

• I have read the contributing guidelines

Code Changes

• Add test cases to all the changes you introduce
• Run poetry all locally to ensure this change passes linter check and tests
• Manually test the changes:
  • Verify the feature/bug fix works as expected in real-world scenarios
  • Test edge cases and error conditions
  • Ensure backward compatibility is maintained
  • Document any manual testing steps performed
• Update the documentation for the changes

Documentation Changes

• Run poetry doc locally to ensure the documentation pages renders correctly
• Check and fix any broken links (internal or external) in the documentation

When running poetry doc, any broken internal documentation links will be reported in the console output like this:

INFO    -  Doc file 'config.md' contains a link 'commands/bump.md#-post_bump_hooks', but the doc 'commands/bump.md' does not contain an anchor '#-post_bump_hooks'.

Expected Behavior

Steps to Test This Pull Request

Additional Context

[codecov]

Codecov Report

❌ Patch coverage is 97.67442% with 1 line in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (v4-10-1@90e5ee7). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
commitizen/commands/changelog.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             v4-10-1    #1599   +/-   ##
==========================================
  Coverage           ?   98.71%           
==========================================
  Files              ?       60           
  Lines              ?     2653           
  Branches           ?        0           
==========================================
  Hits               ?     2619           
  Misses             ?       34           
  Partials           ?        0           

Flag	Coverage Δ
unittests	98.71% <97.67%> (?)

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[bearomorphism]

Now all assert are wrapped in if TYPE_CHECKING: