Update dependency grunt-contrib-qunit to v6

[mend-for-github-com]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
grunt-contrib-qunit	^1.2.0 -> ^6.0.0

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Release Notes

gruntjs/grunt-contrib-qunit

v6.1.0

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• Migrate reporting logic to QUnit.on() events API db80b86
• Add docs for qunit.on.* events, and fix various links 72a71b0

v6.0.0

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• Update to Puppeteer 9 43f7139
• Clean up internal loops in console and pageerror event handlers f50ed47

v5.1.1

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• docs: Update outdated links and fix syntax error 03aeef4

v5.1.0

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• Restore page timeout handling and fail.timeout event 5ba6324
• readme: Fix broken markdown link (#​172) f558142
• Update to Puppeteer 5 ca15b69

v5.0.1

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• Restore page timeout handling and fail.timeout event 5ba6324
• Update to Puppeteer 5 ca15b69

v4.0.0

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v3.1.0

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v3.0.1

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v3.0.0

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v2.0.0

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