chore(deps): update dependency knex to v0.21.8

[mend-for-github-com[bot]]

This PR contains the following updates:

Package	Type	Update	Change
knex (source)	dependencies	patch	0.21.7 -> 0.21.8

By merging this PR, the issue #38 will be automatically resolved and closed:

Severity	CVSS Score	CVE
High	7.5	CVE-2019-20149
High	7.5	CVE-2022-38900
High	7.3	CVE-2020-7788

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Release Notes

knex/knex (knex)

### [`v0.21.8`](https://togithub.com/knex/knex/blob/HEAD/CHANGELOG.md#0218---27-October-2020) [Compare Source](https://togithub.com/knex/knex/compare/23073fa83dfb4bf0ecb204c9ae1f720cd22f41ed...2bcaf51f9d025c9c8631e357da16e3cb3224792c) ##### Bug fixes: - MSSQL: Escape properly if literal '?' is needed [#​4053](https://togithub.com/knex/knex/issues/4053) - Make toQuery behavior consistent with pre-0.21.7 (do not break on empty builder) [#​4083](https://togithub.com/knex/knex/issues/4083) - Fix comment escaping for MySQL and PostgreSQL [#​4084](https://togithub.com/knex/knex/issues/4084)

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