Update dependency browserslist to v4.21.3

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
browserslist	4.21.2 -> 4.21.3

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Release Notes

browserslist/browserslist

### [`v4.21.3`](https://togithub.com/browserslist/browserslist/blob/HEAD/CHANGELOG.md#​4213) [Compare Source](https://togithub.com/browserslist/browserslist/compare/4.21.2...4.21.3) - Improved unknown region and unknown feature error (by Alexander Chabin).

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