Update dependency ajv to v8

Author: renovate[bot]

packages/admin-api-schema/package.json

@@ -26,7 +26,7 @@
   },
   "dependencies": {
     "@tryghost/errors": "^1.0.0",
-    "ajv": "^6.12.6",
+    "ajv": "^8.0.0",
     "lodash": "^4.17.11"
   }
 }

yarn.lock

@@ -1370,7 +1370,7 @@ acorn@^8.5.0, acorn@^8.7.1:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.7.1.tgz#0197122c843d1bf6d0a5e83220a788f278f63c30"
   integrity sha512-Xx54uLJQZ19lKygFXOWsscKUbsBZW0CPykPhVQdhIeIwrbPmJzqeASDInc8nKBnp/JT6igTs82qPXz069H8I/A==
 
-ajv@^6.10.0, ajv@^6.12.4, ajv@^6.12.6:
+ajv@^6.10.0, ajv@^6.12.4:
   version "6.12.6"
   resolved "https://registry.yarnpkg.com/ajv/-/ajv-6.12.6.tgz#baf5a62e802b07d977034586f8c3baf5adf26df4"
   integrity sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==
@@ -1380,7 +1380,7 @@ ajv@^6.10.0, ajv@^6.12.4, ajv@^6.12.6:
     json-schema-traverse "^0.4.1"
     uri-js "^4.2.2"
 
-ajv@^8.0.1:
+ajv@^8.0.0, ajv@^8.0.1:
   version "8.11.0"
   resolved "https://registry.yarnpkg.com/ajv/-/ajv-8.11.0.tgz#977e91dd96ca669f54a11e23e378e33b884a565f"
   integrity sha512-wGgprdCvMalC0BztXvitD2hC04YffAvtsUn93JbGXYLAtCUO4xd17mCCZQxUOItiBwZvJScWo8NIvQMQ71rdpg==