Update changelogs from fern repo (#3507)

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2026-02-05.mdx

@@ -1,3 +1,7 @@
+## 3.64.6
+**`(fix):`** Fix `fern generator upgrade` failing when encountering unrecognized generator names. Previously, an unrecognized generator (e.g. `fernapi/java-model`) would block the entire upgrade process. Now unrecognized generators are skipped with a warning, allowing the remaining generators to be upgraded. Also adds support for the `java-model` legacy generator name alias.
+
+
 ## 3.64.5
 **`(fix):`** Add support for legacy generator names (`fernapi/java-model`, `fernapi/fern-typescript`) used in older IR version configurations.