Fix Rack HTTP status code deprecation warnings

[lxyhan]

Proposed Changes

Fix Rack HTTP status code deprecation warnings by updating deprecated symbols to their modern equivalents:

• Replace :payload_too_large with :content_too_large (HTTP 413)
• Replace :unprocessable_entity with :unprocessable_content (HTTP 422)

Motivation: Rack PR #2137 deprecated these symbols. This change eliminates deprecation warnings when running tests and ensures compatibility with future Rack versions.

Screenshots of your changes (if applicable)

Associated documentation repository pull request (if applicable)

Type of Change

(Write an X or a brief description next to the type or types that best describe your changes.)

Type	Applies?
🚨 Breaking change (fix or feature that would cause existing functionality to change)
✨ New feature (non-breaking change that adds functionality)
🐛 Bug fix (non-breaking change that fixes an issue)	x
🎨 User interface change (change to user interface; provide screenshots)
♻️ Refactoring (internal change to codebase, without changing functionality)
🚦 Test update (change that only adds or modifies tests)
📦 Dependency update (change that updates a dependency)
🔧 Internal (change that only affects developers or continuous integration)

Checklist

(Complete each of the following items for your pull request. Indicate that you have completed an item by changing the [ ] into a [x] in the raw text, or by clicking on the checkbox in the rendered description on GitHub.)

Before opening your pull request:

• I have performed a self-review of my changes.
  • Check that all changed files included in this pull request are intentional changes.
  • Check that all changes are relevant to the purpose of this pull request, as described above.
• I have added tests for my changes, if applicable.
  • This is required for all bug fixes and new features.
• I have updated the project documentation, if applicable.
  • This is required for new features.
• If this is my first contribution, I have added myself to the list of contributors.

After opening your pull request:

• I have updated the project Changelog (this is required for all changes).
• I have verified that the pre-commit.ci checks have passed.
• I have verified that the CI tests have passed.
• I have reviewed the test coverage changes reported by Coveralls.
• I have requested a review from a project maintainer.

Questions and Comments

(Include any questions or comments you have regarding your changes.)

[lxyhan]

Hi @david-yz-liu , after speaking with @freyazjiner, I believe that both her and I are experience the same issue with the coveralls parallel step of the CI failing. I will try to debug the issue with her tonight and work on my other PR in the meantime.

Update: just learned that Freya has asked you about the issue and that I can proceed with a review request, hope it gets resolved soon; I've requested a review!

[david-yz-liu]

@lxyhan this is good, please just update the Changelog. Make sure to include the PR number in the changelog entry (I forgot to mention this on your previous PR).

Don't worry about the Coveralls failure, I think that's just their server being flaky, and isn't something that's worth looking into.

[coveralls]

Pull Request Test Coverage Report for Build 18018678414

Details

• 96 of 105 (91.43%) changed or added relevant lines in 34 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 91.838%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
app/controllers/api/tags_controller.rb	1	2	50.0%
app/controllers/assignments_controller.rb	0	1	0.0%
app/controllers/automated_tests_controller.rb	2	3	66.67%
app/controllers/groups_controller.rb	2	3	66.67%
app/controllers/api/users_controller.rb	1	3	33.33%
app/controllers/api/courses_controller.rb	0	3	0.0%

Totals
Change from base Build 17982712340:	0.0%
Covered Lines:	42292
Relevant Lines:	45323

---

💛 - Coveralls

[david-yz-liu]

This line should not have been changed (please look carefully at the diffs on GitHub as part of your self-review before requesting a review)

[david-yz-liu]

Nice work, @lxyhan!