Bump grunt-contrib-concat from 2.0.0 to 2.1.0 (#858)

Bumps [grunt-contrib-concat](https://github.com/gruntjs/grunt-contrib-concat) from 2.0.0 to 2.1.0.
- [Release notes](https://github.com/gruntjs/grunt-contrib-concat/releases)
- [Changelog](https://github.com/gruntjs/grunt-contrib-concat/blob/main/CHANGELOG)
- [Commits](gruntjs/grunt-contrib-concat@v2.0.0...v2.1.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jeffrey Warren <jeff@unterbahn.com>