Update dependency grunt-contrib-clean to v2

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
grunt-contrib-clean	devDependencies	major	1.1.0 -> 2.0.0

---

Release Notes

gruntjs/grunt-contrib-clean

### [`v2.0.0`](https://togithub.com/gruntjs/grunt-contrib-clean/compare/v1.1.0...v2.0.0) [Compare Source](https://togithub.com/gruntjs/grunt-contrib-clean/compare/v1.1.0...v2.0.0)

---

Renovate configuration

:date: Schedule: At any time (no schedule defined).

:vertical_traffic_light: Automerge: Disabled by config. Please merge this manually once you are satisfied.

:recycle: Rebasing: Whenever PR becomes conflicted, or if you modify the PR title to begin with "rebase!".

:no_bell: Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by Renovate Bot. View repository job log here.