[Eduardo Villalpando Mello (edvilme)]

Summary

Retire the duplicated localization automation now maintained in microsoft/vscode-python-ci.

• Remove .github/actions/localization/action.yml, scripts/localization.py, and its regression tests.
• Remove only the corresponding localization test/lint commands from nox; preserve all runtime package commands.
• Remove the README's Shared localization automation section; shared tooling PRs #14 and #15 are merged.

No Python/TypeScript runtime libraries, source strings, package versions, credentials, translation data, or release settings change. Existing callers pinned to historical commits remain usable; this PR does not delete tags or rewrite history. New callers must use microsoft/vscode-python-ci/actions/localization, and Azure tooling checkouts must use that repository with the unchanged scripts/localization.py interface.

Validation

• Existing Python runtime tests: 333 passed, 2 skipped.
• Black, Flake8, and isort checks passed for noxfile.py.
• Nox session discovery and version synchronization passed.
• Recorded each nox session's commands against origin/main: all non-localization install/test/lint commands are unchanged.
• Removed paths and git diff --check verified.
• Earlier rollout validation: two successful GitHub localization runs each for Black, Flake8, isort, Mypy, Pylint, autopep8, and the Python Environments migration branch. These were synchronized no-ops, not changed-string submissions.

Draft / merge readiness

This PR intentionally remains a draft. The default-branch GitHub caller audit still finds:

• Merge Python Environments #2010; its main workflow still uses the old action.
• Merge Python Debugger #1143, migrating its GitHub action and stable/pre-release Azure tooling references.
• Complete safe, non-publishing Azure localization import/package validation, including service-connection access to vscode-python-ci. GitHub tag/release creation must also be disabled; publishExtension: false alone is not sufficient evidence.
• Review remaining Azure/release-branch/unpinned consumers before marking ready. The default-branch GitHub search is not an exhaustive audit of every caller.

The two confirmed remaining workflows pin the historical 6b4a3573e7e7a9fe1e468e129544432278aec2d6 revision, so deleting the action on the new main revision does not immediately break those pinned workflows.