Remove unused file current-projects-check.html

### Prerequisite
1. Be a member of Hack for LA. (There are no fees to join.) If you have not joined yet, please follow the steps on our [Getting Started page](https://www.hackforla.org/getting-started).
2. Please make sure you have read our **[Hack for LA Contributing Guide](https://github.com/hackforla/website/blob/gh-pages/CONTRIBUTING.md)** before you claim/start working on an issue.

### Overview
As developers we need to remove the unused file `_includes/current-projects-check.html` in order to keep the codebase clear and avoid confusion.

### Action Items
- [ ] Delete the file `_includes/current-projects-check.html`

### Resources/Instructions
- Website page with issue: https://www.hackforla.org/projects-check/
- File on GitHub: https://github.com/hackforla/website/blob/gh-pages/_includes/current-projects-check.html
- #3487
- #6200
- #6243
- #5978
- See associated ER for this issue: #7778