Bump grunt from 0.4.5 to 1.5.3 in /mapstory/static

Bumps [grunt](https://github.com/gruntjs/grunt) from 0.4.5 to 1.5.3.
- [Release notes](https://github.com/gruntjs/grunt/releases)
- [Changelog](https://github.com/gruntjs/grunt/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt@v0.4.5...v1.5.3)

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

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

Author: dependabot[bot]