chore: update dependencies and changelog for v1.31.2

Bumps runtime dependencies axios (^1.18.1 -> ^1.20.0) and qs
(^6.15.2 -> ^6.16.0), plus dev dependencies @babel/eslint-parser,
@slack/bolt, @types/lodash, jest, nock, ts-jest and webpack.

npm audit across the dependency tree before and after:

  before   17 vulnerabilities  (3 critical, 6 high, 7 moderate, 1 low)
  after    10 vulnerabilities  (3 critical, 1 high, 5 moderate, 1 low)

Seven resolved, five of them high severity. The qs advisory is the
consumer-facing one, since qs is a runtime dependency. The ten that
remain are all dev-only (babel-traverse, mocha, nyc, istanbul,
serialize-javascript, uuid, diff, mochawesome) and are not shipped.

Verified with npm run lint (clean) and npm run test:unit (686 passing).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: cs-raj

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## [v1.31.2](https://github.com/contentstack/contentstack-management-javascript/tree/v1.31.2) (2026-09-22)
+
+- Resolved security vulnerabilities in dependencies
+
 ## [v1.31.1](https://github.com/contentstack/contentstack-management-javascript/tree/v1.31.1) (2026-07-30)
 
 - Snyk fixes