This PR prepares the release 1.15.2.

Summary by cubic

Prepares axios 1.15.2 patch release by bumping version across the repo. No functional changes; only metadata updates and the exported VERSION constant.

Description

• Summary of changes: Update VERSION in lib/env/data.js and bump version in package.json and package-lock.json to 1.15.2.
• Reasoning: Align source and package metadata for the 1.15.2 release.
• Additional context: No runtime or API changes.

Docs

• Update any visible version references and changelog in /docs/ to 1.15.2.

Testing

• No tests added or modified. None needed since this is a version-only bump.

Semantic version impact

• Patch release (1.15.2). No breaking changes.

^{Written for commit f46699f. Summary will update on new commits.}