Update version in fern.config.json to 5.59.0

Update Fern CLI to latest deployment mode, faster page load speeds.

Author: fern-support

fern/fern.config.json

@@ -1,4 +1,4 @@
 {
   "organization": "vapi",
-  "version": "5.46.1"
+  "version": "5.59.0"
 }