fix: packages/config-loader/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-AJV-15274295

Author: snyk-io[bot]

packages/config-loader/package.json

@@ -38,7 +38,7 @@
     "@backstage/errors": "workspace:^",
     "@backstage/types": "workspace:^",
     "@types/json-schema": "^7.0.6",
-    "ajv": "^8.10.0",
+    "ajv": "^8.18.0",
     "chokidar": "^3.5.2",
     "fs-extra": "10.1.0",
     "json-schema": "^0.4.0",