Support auto-detecting Actions workflows

[mbg]

This modifies getRawLanguagesInRepo to automatically detect Actions workflows. Linguist does not class those as a language, and so we failed to automatically detect them before.

I chose to implement this by checking for a non-empty .github/workflows directory, relative to source-root.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Confirm the readme has been updated if necessary.
• Confirm the changelog has been updated if necessary.

[Copilot]

Pull Request Overview

This PR adds automatic detection of GitHub Actions workflows to the CodeQL Action's language detection system. Since GitHub's Linguist API doesn't classify Actions workflows as a language, this enhancement enables the CodeQL Action to detect them by checking for a non-empty .github/workflows directory.

Key changes:

• Added hasActionsWorkflows() function to detect workflows by checking for files in .github/workflows
• Modified getRawLanguagesInRepo() to include "actions" when workflows are detected
• Updated function signatures throughout the codebase to pass sourceRoot parameter

Reviewed Changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated no comments.

File	Description
src/config-utils.ts	Implements workflow detection logic and updates language detection functions
src/config-utils.test.ts	Updates test calls to include new sourceRoot parameter
lib/config-utils.js	Generated JavaScript equivalent of TypeScript changes
lib/config-utils.test.js	Generated JavaScript equivalent of test changes

Comments suppressed due to low confidence (1)

src/config-utils.ts:340

• The function will throw an exception if the .github/workflows directory doesn't exist, causing lstatSync to fail. This should be wrapped in a try-catch block or use fs.existsSync() first to check if the path exists before calling lstatSync.

  const stats = fs.lstatSync(workflowsPath);
  return stats.isDirectory() && fs.readdirSync(workflowsPath).length > 0;

[henrymercer]

We have an implementation of language autodetection in the CLI which I'd like to see us use in the Action too, but given the simplicity of this PR this looks good as a quick fix.