fix: upgrade ajv to address dependabot alerts (#1999)

resolves
https://github.com/braintrustdata/braintrust-sdk-javascript/security/dependabot/585
resolves
https://github.com/braintrustdata/braintrust-sdk-javascript/security/dependabot/586
resolves
https://github.com/braintrustdata/braintrust-sdk-javascript/security/dependabot/242

Author: AbhiPrasad

js/package.json

@@ -198,7 +198,7 @@
     "@apm-js-collab/code-transformer": "^0.12.0",
     "@next/env": "^14.2.3",
     "@vercel/functions": "^1.0.2",
-    "ajv": "^8.17.1",
+    "ajv": "^8.20.0",
     "argparse": "^2.0.1",
     "boxen": "^8.0.1",
     "chalk": "^4.1.2",