And use script to update PR description with Cypress status
## Summary by CodeRabbit
- **Enhancements**
- Improved GitHub Actions workflows for PR automation and Cypress tests.
- Enhanced test failure messages with links to Cypress dashboard and
flaky test identification.
- **User Experience**
- Cypress test status messages now include emoji prefixes for "tip"
(green) and "caution" (red) alerts.
- **Bug Fixes**
- Corrected error handling in scripts to provide more accurate failure
statuses.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Replacing more of `nefrob/pr-description@v1.1.2` with our GitHub Script.
This is moving towards Javascript CI, and hopefully an unit-testable CI.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Chores**
- Replaced `nefrob/pr-description` action with `actions/github-script`
for handling test responses in PR automation.
- Improved guidance on modifying PR body for correct tag usage and
linked to relevant documentation.
- Enhanced script content to handle warnings and failures more
effectively in PR workflow automation.
- **New Features**
- Updated the `write-cypress-status` script to support different alert
types and prefixes, ensuring better validation and formatting of alerts.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->