Add CodeQL scanning workflow

[adharsh277]

Add CodeQL scanning workflow for security analysis

This PR adds a GitHub Actions workflow using CodeQL to enable automatic code scanning for potential security vulnerabilities. Currently, Flatcar repositories using CodeQL-based rulesets are not all properly configured to run the scanner, which leads to stuck checks and confusion for contributors. This fixes that by explicitly adding a .github/workflows/codeql.yml file.

The workflow is configured to scan for C/C++ vulnerabilities and will run on every push, pull request to the main branch, and weekly via a scheduled cron job.

How to use

Once this PR is merged, GitHub's Security tab will begin showing CodeQL analysis results. No manual intervention is required unless further customization is needed for supported languages.

Testing done

This workflow file is based on GitHub's officially supported CodeQL scanning configuration. Manual verification was done in a GitHub Codespace with the following steps:

• Created .github/workflows/codeql.yml using nano
• Committed and pushed the changes on the enable-codeql-integration branch
• Verified syntax correctness and push success

✅ No changelog entry is needed as this is a DevOps/security CI config addition.

• Changelog entries not applicable (non-user-facing DevOps addition)
• Verified correct file path and GitHub Actions syntax

[adharsh277]

Hi @John15321 sir ,
I’ve submitted a PR to add the missing CodeQL scanning workflow to this repository, as part of the integration mentioned in this issue.
🔗 PR: #1803 - Add CodeQL scanning workflow
This should ensure proper security analysis for C/C++ code and resolve the issue where CodeQL-based rulesets were stuck due to scanning not being enabled.
I apologize for not waiting for your response before contributing — I got a bit eager to help out and proceeded after preparing everything. Please let me know if you'd prefer any changes or if you'd like me to apply the same fix to other Flatcar repositories as well.

Thanks!
— @adharsh277

[John15321]

Hi @John15321 sir , I’ve submitted a PR to add the missing CodeQL scanning workflow to this repository, as part of the integration mentioned in this issue. 🔗 PR: #1803 - Add CodeQL scanning workflow This should ensure proper security analysis for C/C++ code and resolve the issue where CodeQL-based rulesets were stuck due to scanning not being enabled. I apologize for not waiting for your response before contributing — I got a bit eager to help out and proceeded after preparing everything. Please let me know if you'd prefer any changes or if you'd like me to apply the same fix to other Flatcar repositories as well.

Thanks! — @adharsh277

Hi @adharsh277,

Thank you so much for your initiative and for submitting the PR! We really appreciate your eagerness to help out and contribute 😄

I’ve left a more detailed response on the original issue, but just wanted to say here as well that your help is truly valued. Thanks again for your proactive support!