chore(deps): update dependency qunit to v2.21.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
qunit (source)	2.20.1 -> 2.21.0

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Release Notes

qunitjs/qunit (qunit)

v2.21.0

Compare Source

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Added

• Assert: Add assert.closeTo(). (Timo Tijhof) #​1735
• Core: Add support for flat preconfig via environment/global variables. (Timo Tijhof)

Deprecated

• Core: Deprecate QUnit.load() and document migration path at https://qunitjs.com/api/QUnit/load/. (Timo Tijhof) #​1743
• Core: Deprecate unset testTimeout for tests taking longer than 3 seconds. (Timo Tijhof) #​1483

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Configuration

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