[typescript-migration] month_dropdown.jsx and month_dropdown_options.jsx

[yuki0410-dev]

name: Migrate month_dropdown.jsx and month_dropdown_options.jsx

Description

Linked issue: #4700

Changes month_dropdown.jsx and month_dropdown_options.jsx was migrated to ts and test

Contribution checklist

• [x] I have followed the contributing guidelines.
• [x] I have added sufficient test coverage for my changes.
• [x] I have formatted my code with Prettier and checked for linting issues with ESLint for code readability.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.07%. Comparing base (1606cf3) to head (a6b82f7).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #4723 +/- ## ========================================== - Coverage 97.16% 97.07% -0.10% ========================================== Files 18 16 -2 Lines 1765 1710 -55 Branches 742 726 -16 ========================================== - Hits 1715 1660 -55 Misses 50 50 ```

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