Persist CodeQL version output to file rather than environment

[mario-campos]

Currently, the output of codeql version is cached and persisted between steps as an environment variable. This is fine, for now, but, as we begin to cache more of the CLI, we should persist that output to a file instead. This PR begins that process by persisting the output of codeql version to $CODEQL_ACTION_TEMP/version.json instead of $CODEQL_ACTION_CLI_VERSION_INFO.

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?

Workflow types:

• Advanced setup - Impacts users who have custom CodeQL workflows.
• Managed - Impacts users with dynamic workflows (Default Setup, Code Quality, ...).

Products:

• Code Scanning - The changes impact analyses when analysis-kinds: code-scanning.
• Code Quality - The changes impact analyses when analysis-kinds: code-quality.

Environments:

• Dotcom - Impacts CodeQL workflows on github.com and/or GitHub Enterprise Cloud with Data Residency.
• GHES - Impacts CodeQL workflows on GitHub Enterprise Server.

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.

How will you know if something goes wrong after this change is released?

• Telemetry - I rely on existing telemetry or have made changes to the telemetry.
  • Alerts - New or existing monitors will trip if something goes wrong with this change.

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

Moves persisted CodeQL CLI version metadata from an environment variable to a temporary JSON file.

Changes:

• Writes and reads version metadata from $CODEQL_ACTION_TEMP/version.json.
• Removes the obsolete environment variable.
• Updates persistence tests.

Show a summary per file

File	Description
src/util.ts	Implements file-based version caching.
src/util.test.ts	Updates cache-reading tests.
src/environment.ts	Removes the old cache environment variable.

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 1
• Review effort level: Balanced