[Security] Bump is-my-json-valid from 2.16.0 to 2.19.0

Bumps [is-my-json-valid](https://github.com/mafintosh/is-my-json-valid) from 2.16.0 to 2.19.0. **This update includes security fixes.**
- [Release notes](https://github.com/mafintosh/is-my-json-valid/releases)
- [Commits](mafintosh/is-my-json-valid@v2.16.0...v2.19.0)

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