docs(bigquery): update changelog with backfilled release notes

Author: meltsufin

java-bigquery/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## [2.65.0](https://github.com/googleapis/google-cloud-java/compare/6bef068b4d8...fabe31c2a9d) (2026-04-13)
+## [2.65.0](https://github.com/googleapis/google-cloud-java/compare/6bef068b4d8...v1.85.0) (2026-04-13)
 
 ### Bug Fixes
 
@@ -11,6 +11,7 @@
 
 * No change
 
+
 ## 2.62.0 (None)
 
 * No change