Enhance Tests: Replace Raw Status Codes with httpx.codes

[mahdirahimi1999]

Description:

This pull request improves the test suite by replacing raw status codes with httpx.codes constants for better readability and consistency with the httpx package conventions.

Changes:

• Replaced raw status code 200 with httpx.codes.OK.value in the tests.
• Replaced raw status code 500 with httpx.codes.INTERNAL_SERVER_ERROR.value in the tests.

Rationale:

• The httpx.codes module provides human-readable status codes, making the tests easier to understand and maintain.
• Replacing raw status codes (e.g., 200, 500) with the corresponding httpx.codes constants improves consistency with the httpx library's intended usage and avoids the use of "magic numbers" in the test code.

Why this PR is Important:

• Improved Readability: Makes the test code more intuitive, especially for contributors unfamiliar with HTTP status codes.
• Better Consistency: Aligns the test code with the httpx package's built-in status code handling.
• Maintainability: Helps prevent errors related to hardcoded status codes by using standardized constants.

Request for Review:

Please review the changes and let me know if any further modifications or refinements are needed. This small enhancement will make the tests more consistent and easier to understand for all contributors.

[mahdirahimi1999]

Hi @tomchristie, could you please review these changes?

[Kludex]

Thanks for the PR @mahdirahimi1999 , but I think this is opinionated, and it doesn't bring much improvement on readability.

Also, PRs that are only refactor, that are a non-clear win, would probably have the same reaction from other maintainers.