Bump shelljs and jshint

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


Removes `shelljs`

Updates `jshint` from 2.11.0 to 2.13.6
- [Release notes](https://github.com/jshint/jshint/releases)
- [Changelog](https://github.com/jshint/jshint/blob/main/CHANGELOG.md)
- [Commits](jshint/jshint@2.11.0...2.13.6)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -51,7 +51,7 @@
     "gulp-webserver": "~0.9.1",
     "gulp-wrap": "~0.14.0",
     "imagemin-pngcrush": "~6.0.0",
-    "jshint": "^2.11.0",
+    "jshint": "^2.13.6",
     "jshint-stylish": "~2.2.1",
     "merge-stream": "^1.0.1",
     "gulp4-run-sequence": "^1.0.0",