Bump grunt from 1.0.4 to 1.5.3 in /ee/vulnerability-dashboard

Bumps [grunt](https://github.com/gruntjs/grunt) from 1.0.4 to 1.5.3.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt@v1.0.4...v1.5.3)

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

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

ee/vulnerability-dashboard/package.json

@@ -21,7 +21,7 @@
   },
   "devDependencies": {
     "eslint": "5.16.0",
-    "grunt": "1.0.4",
+    "grunt": "1.5.3",
     "htmlhint": "0.11.0",
     "lesshint": "6.3.6",
     "sails-hook-grunt": "^5.0.0",