Bump is-my-json-valid from 2.15.0 to 2.20.6

Bumps [is-my-json-valid](https://github.com/mafintosh/is-my-json-valid) from 2.15.0 to 2.20.6.
- [Release notes](https://github.com/mafintosh/is-my-json-valid/releases)
- [Commits](mafintosh/is-my-json-valid@v2.15.0...v2.20.6)

---
updated-dependencies:
- dependency-name: is-my-json-valid
  dependency-type: indirect
...

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