Implement SSL Certificate Monitor workflow

[meteorcloudy]

This PR introduces a new SSL certificate monitoring workflow for Bazel domains.

Core Changes:

• Automated SSL Check: Adds a daily workflow and Python script to monitor SSL certificate expirations.
• Intelligent Issue Reporting: Creates a GitHub issue when certificates are expiring, or adds a comment to an existing open issue to avoid duplicates.
• PR Validation: Automatically validates changes to the monitoring script or domain configuration in Pull Requests.
• Configuration: Includes a customizable list of domains and warning thresholds in .github/config/ssl_domains.yaml.

[gemini-code-assist]

Code Review

This pull request introduces a new, well-structured Python script and configuration file for monitoring SSL certificate expiration, which is a great improvement for infrastructure reliability. My review identifies a couple of areas in the new script where robustness and maintainability can be enhanced. Specifically, I've suggested replacing a broad exception with more specific ones to avoid masking potential bugs, and removing a redundant and misleading code block to improve clarity. These changes will make the script more robust and easier for future developers to maintain.

[meteorcloudy]

I have addressed both PR review suggestions:

1. Narrowed the broad Exception catch to (OSError, ValueError) in check_all().
2. Removed the redundant DEFAULT_CONFIG_PATH check in main() as it is already handled by the SSLMonitor constructor.

[meteorcloudy]

Tested in #28200 and it successfully generated #28201