chore(deps): bump grunt from 1.5.2 to 1.5.3 in /tests/apps/multi

Bumps [grunt](https://github.com/gruntjs/grunt) from 1.5.2 to 1.5.3.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](https://github.com/gruntjs/grunt/compare/v1.5.2...v1.5.3)

---
updated-dependencies:
- dependency-name: grunt
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

tests/apps/multi/package.json

@@ -2,7 +2,7 @@
   "author": "Al Johri",
   "dependencies": {
     "bower": "^1.8.0",
-    "grunt": "~1.5.2",
+    "grunt": "~1.5.3",
     "grunt-cli": "~1.4.3",
     "grunt-contrib-compass": "~1.1.1",
     "load-grunt-tasks": "~5.1.0",