Python: Disable standard library extraction on GHES

[henrymercer]

This has been the CLI default for some time now that Python analysis contains models of the standard library. However due to the default value of the feature flag we have been manually enabling standard library extraction on GHES.

This PR cleans up that feature and removes the override logic.

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.
• Other first-party - The changes impact other first-party analyses.

Environments:

• GHES - Impacts CodeQL workflows on GitHub Enterprise Server.

How did/will you validate this change?

• None - I am not validating these changes.

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?

If there's a subtle bug here, we'd realistically probably only catch it in the release QA process.

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

Removes the now-unneeded feature flag and init-time override that forced Python standard library extraction on GHES, aligning the Action’s behavior with the CodeQL CLI default (stdlib models instead of extraction) and documenting the change.

Changes:

• Remove the PythonDefaultIsToNotExtractStdlib tools feature and corresponding Action feature flag/config.
• Delete the init-time logic that conditionally exported CODEQL_EXTRACTOR_PYTHON_EXTRACT_STDLIB=true when the flag wasn’t rolled out.
• Add a CHANGELOG entry describing the GHES behavior change and expected impact.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/tools-features.ts	Drops the tools feature enum entry used to gate the previous Python stdlib extraction override.
src/init-action.ts	Removes the Python stdlib extraction override/export logic from init.
src/feature-flags.ts	Removes the corresponding feature flag enum value and featureConfig entry.
CHANGELOG.md	Documents that Python analysis on GHES no longer extracts the standard library (uses models instead).
lib/init-action.js	Generated output reflecting removal of the override logic and feature config.
lib/init-action-post.js	Generated output reflecting removal of the feature config entry.
lib/analyze-action.js	Generated output reflecting removal of the feature config entry.
lib/analyze-action-post.js	Generated output reflecting removal of the feature config entry.
lib/autobuild-action.js	Generated output reflecting removal of the feature config entry.
lib/setup-codeql-action.js	Generated output reflecting removal of the feature config entry.
lib/resolve-environment-action.js	Generated output reflecting removal of the feature config entry.
lib/start-proxy-action.js	Generated output reflecting removal of the feature config entry.
lib/start-proxy-action-post.js	Generated output reflecting removal of the feature config entry.
lib/upload-lib.js	Generated output reflecting removal of the feature config entry.
lib/upload-sarif-action.js	Generated output reflecting removal of the feature config entry.
lib/upload-sarif-action-post.js	Generated output reflecting removal of the feature config entry.