fix(deps): update @descope/core-js-sdk to ^2.64.0 (#751)

Picks up core-js-sdk 2.64.0, which adds Cloudflare status code 520
("Web Server Returned an Unknown Error") to the HTTP client's transient
retry list (descope/descope-js#1423). This propagates the retry-on-520
behavior to node-sdk, matching go-sdk, python-sdk, java, dotnet and php.

Relates to descope/etc#14039

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dorsha

package-lock.json

@@ -102,7 +102,7 @@
     "typescript": "^4.6.4"
   },
   "dependencies": {
-    "@descope/core-js-sdk": "^2.58.0",
+    "@descope/core-js-sdk": "^2.64.0",
     "cross-fetch": "^4.0.0",
     "jose": "5.2.2",
     "tslib": "^2.0.0"