Update unit test packages

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
@types/chai	devDependencies	patch	4.2.11 -> 4.2.12
mocha (source)	devDependencies	patch	8.1.1 -> 8.1.3
sinon (source)	devDependencies	patch	9.0.2 -> 9.0.3

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Release Notes

mochajs/mocha

v8.1.3

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🐛 Fixes

• #​4425: Restore Mocha.utils.lookupFiles() and Webpack compatibility (both broken since v8.1.0); Mocha.utils.lookupFiles() is now deprecated and will be removed in the next major revision of Mocha; use require('mocha/lib/cli').lookupFiles instead (@​boneskull)

v8.1.2

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🐛 Fixes

• #​4418: Fix command-line flag incompatibility in forthcoming Node.js v14.9.0 (@​boneskull)
• #​4401: Fix missing global variable in browser (@​irrationnelle)

🔒 Security Fixes

• #​4396: Update many dependencies (@​GChuf)

📖 Documentation

• Various fixes by @​sujin-park, @​wwhurin & @​Donghoon759

sinonjs/sinon

v9.0.3

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==================

• Upgrade nise to latest
• Upgrade @​sinonjs/samsam to latest

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