Add AzDO pipeline to bump decoupled deps and update API docs after publish

[iclanton]

Summary

Adds a new AzDO pipeline (npm-post-publish.yaml) that runs automatically after either npm publish pipeline completes. Currently it bumps decoupled local dependencies to the latest published versions and opens a GitHub PR with the changes. It is also designed to support a future stage that regenerates API markdown documentation on rushstack-websites using api-documenter.

Example PR here: #5660

Depends on #5663

What it does

Stage 1: Bump decoupled local dependencies

1. Waits a configurable delay (default 5 min) for packages to propagate to npm
2. Runs bump-decoupled-local-dependencies from repo-toolbox
3. Runs rush update to refresh the lockfile
4. Commits changes and generates empty change files via rush change --bulk --bump-type none
5. Force-pushes to automated/bump-decoupled-deps and creates/updates a GitHub PR

Stage 2: Update API documentation (planned)

Once the publish-api-artifact PR (#5663) merges, a second stage will be added to:

1. Download the *.api.json artifact from the triggering publish pipeline
2. Run api-documenter markdown to generate updated API reference pages
3. Open a PR against microsoft/rushstack-websites with the refreshed markdown

Files

• npm-post-publish.yaml — Main pipeline, triggered by both rushstack NPM Publish and rushstack NPM Publish (rush)
• templates/push-and-create-github-pr.yaml — Reusable template for force-pushing a branch and creating/updating a GitHub PR via the REST API (supports a WorkingDirectory parameter for multi-repo checkout scenarios)
• templates/post-publish.yaml — Fix lib/ → lib-commonjs/ path for repo-toolbox invocations