chore(deps): bump ajv and @asyncapi/parser in /scripts/converter

Bumps [ajv](https://github.com/ajv-validator/ajv) and [@asyncapi/parser](https://github.com/asyncapi/parser-js). These dependencies needed to be updated together.

Updates `ajv` from 5.5.2 to 8.12.0
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v5.5.2...v8.12.0)

Updates `@asyncapi/parser` from 2.0.3 to 2.1.2
- [Release notes](https://github.com/asyncapi/parser-js/releases)
- [Changelog](https://github.com/asyncapi/parser-js/blob/master/.releaserc)
- [Commits](asyncapi/parser-js@v2.0.3...v2.1.2)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
- dependency-name: "@asyncapi/parser"
  dependency-type: indirect
...

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