chore(deps-dev): bump @types/jest from 26.0.19 to 26.0.20

Bumps [@types/jest](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/jest) from 26.0.19 to 26.0.20.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/jest)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>