Bump ajv from 5.5.2 to 6.12.3

Bumps [ajv](https://github.com/ajv-validator/ajv) from 5.5.2 to 6.12.3.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v5.5.2...v6.12.3)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: direct:development
...

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

Author: dependabot[bot]

package-lock.json

@@ -606,7 +606,7 @@
     "@typescript-eslint/eslint-plugin": "^4.31.1",
     "@typescript-eslint/parser": "^4.31.1",
     "acorn": "^7.4.0",
-    "ajv": "^5.0.0",
+    "ajv": "^6.12.3",
     "del": "^2.2.2",
     "download": "^8.0.0",
     "eslint": "^7.32.0",