Bump shelljs and grunt-contrib-jshint in /lib/js

Removes [shelljs](https://github.com/shelljs/shelljs). It's no longer used after updating ancestor dependency [grunt-contrib-jshint](https://github.com/gruntjs/grunt-contrib-jshint). These dependencies need to be updated together.


Removes `shelljs`

Updates `grunt-contrib-jshint` from 2.1.0 to 3.2.0
- [Release notes](https://github.com/gruntjs/grunt-contrib-jshint/releases)
- [Changelog](https://github.com/gruntjs/grunt-contrib-jshint/blob/main/CHANGELOG)
- [Commits](https://github.com/gruntjs/grunt-contrib-jshint/compare/v2.1.0...v3.2.0)

---
updated-dependencies:
- dependency-name: shelljs
  dependency-type: indirect
- dependency-name: grunt-contrib-jshint
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/lib/js/package.json b/lib/js/package.json
index b2420bd..ab0cc6b 100644
--- a/lib/js/package.json
+++ b/lib/js/package.json
@@ -16,7 +16,7 @@
     "grunt": "^1.4.1",
     "grunt-cli": "^1.4.3",
     "grunt-contrib-concat": "~1.0",
-    "grunt-contrib-jshint": "~2.1",
+    "grunt-contrib-jshint": "~3.2",
     "grunt-contrib-qunit": "~3.1",
     "grunt-contrib-uglify": "~4.0",
     "grunt-jsdoc": "~2.4",