Chore: Removed yarn test from contributing guide (#4879)

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## Because
<!-- Summarize the purpose or reasons for this PR, e.g. what problem it
solves or what benefit it provides. -->
`yarn test` is no longer used in The Odin Project's main repo since
React was removed, and needs to be removed from CONTRIBUTING.md
instructions.

## This PR
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changes. -->
- `yarn test` removed from 'Testing Changes Locally' section in
CONTRIBUTING.md

## Issue
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with the issue number, e.g. Closes #2013.

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Closes #4856

## Additional Information
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## Pull Request Requirements
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e.g. [x]. After you create the PR, they will become checkboxes that you
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- [x] I have thoroughly read and understand [The Odin Project
Contributing
Guide](https://github.com/TheOdinProject/theodinproject/blob/main/CONTRIBUTING.md)
- [x] The title of this PR follows the `keyword: brief description of
change` format, using one of the following keywords:
    - `Feature` - adds new or amends existing user-facing behavior
- `Chore` - changes that have no user-facing value, refactors,
dependency bumps, etc
    - `Fix` - bug fixes
-   [x] The `Because` section summarizes the reason for this PR
- [x] The `This PR` section has a bullet point list describing the
changes in this PR
- [ ] I have verified all tests and linters pass after making these
changes.
- [x] If this PR addresses an open issue, it is linked in the `Issue`
section
-   [ ] If applicable, this PR includes new or updated automated tests

CONTRIBUTING.md

@@ -5,6 +5,7 @@ Thank you for expressing interest in contributing to The Odin Project (TOP) web
 This contributing guide assumes you have followed the instructions in our general contributing guide to fork and clone our web app repo.
 
 ## Table of Contents
+
 - [How to Contribute](#how-to-contribute)
   - [Running The Odin Project Locally](#running-the-odin-project-locally)
   - [Adding Curriculum Content](#adding-curriculum-content)
@@ -35,5 +36,4 @@ Before submitting a pull request (PR) to our web app repo, you should run the fo
 rubocop
 yarn lint
 rspec
-yarn test
 ```