chore(deps-dev): bump grunt from 1.5.3 to 1.6.1 (#438)

Bumps [grunt](https://github.com/gruntjs/grunt) from 1.5.3 to 1.6.1.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt@v1.5.3...v1.6.1)

---
updated-dependencies:
- dependency-name: grunt
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -30,7 +30,7 @@
     "finalhandler": "1.2.0",
     "geckodriver": "3.2.0",
     "global-replaceify": "1.0.0",
-    "grunt": "1.5.3",
+    "grunt": "1.6.1",
     "grunt-babel": "8.0.0",
     "grunt-contrib-concat": "2.1.0",
     "grunt-replace": "2.0.2",