Update dependency i18next to v21.10.0

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
i18next (source)	21.9.2 -> 21.10.0

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Release Notes

i18next/i18next

### [`v21.10.0`](https://togithub.com/i18next/i18next/blob/HEAD/CHANGELOG.md#​21100) [Compare Source](https://togithub.com/i18next/i18next/compare/v21.9.2...v21.10.0) - Add formatter cache [1843](https://togithub.com/i18next/i18next/pull/1843)

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