Bump ajv and less

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

Updates `ajv` from 4.11.8 to 8.12.0
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@4.11.8...v8.12.0)

Updates `less` from 2.7.3 to 4.1.3
- [Release notes](https://github.com/less/less.js/releases)
- [Changelog](https://github.com/less/less.js/blob/master/CHANGELOG.md)
- [Commits](less/less.js@v2.7.3...v4.1.3)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
- dependency-name: less
  dependency-type: indirect
...

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

Author: dependabot[bot]