Update dependency grunt to v1.5.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
grunt (source)	1.5.0 -> 1.5.1

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Release Notes

gruntjs/grunt

### [`v1.5.1`](https://togithub.com/gruntjs/grunt/releases/v1.5.1) [Compare Source](https://togithub.com/gruntjs/grunt/compare/v1.5.0...v1.5.1) - Merge pull request [#​1742](https://togithub.com/gruntjs/grunt/issues/1742) from gruntjs/update-symlink-test [`ad22608`](https://togithub.com/gruntjs/grunt/commit/ad22608) - Fix symlink test [`0652305`](https://togithub.com/gruntjs/grunt/commit/0652305)

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Configuration

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