Mypy improvement

[Lee-W]

Description

Checklist

• Add test cases to all the changes you introduce
• Run ./scripts/format and ./scripts/test locally to ensure this change passes linter check and test
• Test the changes on the local machine manually
• Update the documentation for the changes

Expected behavior

Steps to Test This Pull Request

Additional context

#1053

[codecov]

Codecov Report

Attention: Patch coverage is 95.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 97.49%. Comparing base (120d514) to head (1eb5aab).
Report is 255 commits behind head on master.

Files	Patch %	Lines
commitizen/commands/check.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1054      +/-   ##
==========================================
+ Coverage   97.33%   97.49%   +0.15%     
==========================================
  Files          42       55      +13     
  Lines        2104     2431     +327     
==========================================
+ Hits         2048     2370     +322     
- Misses         56       61       +5     

Flag	Coverage Δ
unittests	97.49% <95.00%> (+0.15%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.