Add basic PR check with CCR-like environment

[mbg]

This adds a basic PR check for a CCR-like environment.

Risk assessment

For internal use only. Please select the risk level of this change:

• Low risk: Changes are fully under feature flags, or have been fully tested and validated in pre-production environments and are highly observable, or are documentation or test only.

Which use cases does this change impact?

• Testing/None - This change does not impact any CodeQL workflows in production.

How did/will you validate this change?

• Unit tests - I am depending on unit test coverage (i.e. tests in .test.ts files).
• End-to-end tests - I am depending on PR checks (i.e. tests in pr-checks).

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

• Rollback - Change can only be disabled by rolling back the release or releasing a new version with a fix.

Are there any special considerations for merging or releasing this change?

• No special considerations - This change can be merged at any time.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Consider adding a changelog entry for this change.
• Confirm the readme and docs have been updated if necessary.

[Copilot]

Pull request overview

This PR adds a new basic PR check to test the CodeQL Action in a CCR (Copilot Code Review) environment. The test configures a custom analysis key to simulate CCR-like conditions.

Changes:

• Added a new test template that sets CODEQL_ACTION_ANALYSIS_KEY environment variable to test CCR-specific behavior
• Generated corresponding GitHub Actions workflow that runs the test across multiple CodeQL versions

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pr-checks/checks/ccr.yml	New test template defining a standard analysis in CCR mode with JavaScript language
.github/workflows/__ccr.yml	Auto-generated workflow file from the template (not reviewed per coding guidelines)