This PR prepares the release 1.16.1.

Summary by cubic

Prepares the axios 1.16.1 release by bumping version numbers. Syncs with v1.x; no functional changes.

Description

• Summary of changes: set VERSION in lib/env/data.js to "1.16.1"; bump versions in package.json and package-lock.json.
• Reasoning: align runtime export and npm metadata for the 1.16.1 patch release.
• Additional context: merged v1.x into the release branch; no code changes beyond version bumps.

Docs

• Update version refs in /docs/ (install snippets, CDN links, badges) to 1.16.1.

Testing

• No tests changed. None needed for a version bump; CI should pass.

Semantic version impact

• Patch release (1.16.1); no breaking changes.

^{Written for commit 56b5460. Summary will update on new commits.}