Bump ajv from 6.12.0 to 6.12.6

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.12.0 to 6.12.6.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v6.12.0...v6.12.6)

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

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

yarn.lock

@@ -757,20 +757,10 @@ ajv-keywords@^3.1.0, ajv-keywords@^3.4.1:
   resolved "https://registry.yarnpkg.com/ajv-keywords/-/ajv-keywords-3.4.1.tgz#ef916e271c64ac12171fd8384eaae6b2345854da"
   integrity sha512-RO1ibKvd27e6FEShVFfPALuHI3WjSVNeK5FIsmme/LYRNxjKuNj+Dt7bucLa6NdSv3JcVTyMlm9kGR84z1XpaQ==
 
-ajv@^6.1.0, ajv@^6.10.2:
-  version "6.12.0"
-  resolved "https://registry.yarnpkg.com/ajv/-/ajv-6.12.0.tgz#06d60b96d87b8454a5adaba86e7854da629db4b7"
-  integrity sha512-D6gFiFA0RRLyUbvijN74DWAjXSFxWKaWP7mldxkVhyhAV3+SWA9HEJPHQ2c9soIeTFJqcSdFDGFgdqs1iUU2Hw==
-  dependencies:
-    fast-deep-equal "^3.1.1"
-    fast-json-stable-stringify "^2.0.0"
-    json-schema-traverse "^0.4.1"
-    uri-js "^4.2.2"
-
-ajv@^6.5.5:
-  version "6.12.3"
-  resolved "https://registry.yarnpkg.com/ajv/-/ajv-6.12.3.tgz#18c5af38a111ddeb4f2697bd78d68abc1cabd706"
-  integrity sha512-4K0cK3L1hsqk9xIb2z9vs/XU+PGJZ9PNpJRDS9YLzmNdX6jmVPfamLvTJr0aDAusnHyCHO6MjzlkAsgtqp9teA==
+ajv@^6.1.0, ajv@^6.10.2, ajv@^6.5.5:
+  version "6.12.6"
+  resolved "https://registry.yarnpkg.com/ajv/-/ajv-6.12.6.tgz#baf5a62e802b07d977034586f8c3baf5adf26df4"
+  integrity sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==
   dependencies:
     fast-deep-equal "^3.1.1"
     fast-json-stable-stringify "^2.0.0"