build(deps-dev): bump ts-jest from 26.5.5 to 26.5.6

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 26.5.5 to 26.5.6.
- [Release notes](https://github.com/kulshekhar/ts-jest/releases)
- [Changelog](https://github.com/kulshekhar/ts-jest/blob/master/CHANGELOG.md)
- [Commits](kulshekhar/ts-jest@v26.5.5...v26.5.6)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]