Changelog for compatibility bugfix release 0.9.4 (#2084)

Summary: Pull Request resolved: #2084

Reviewed By: SebastianAment

Differential Revision: D51031190

Pulled By: Balandat

fbshipit-source-id: 904df93edd8db6efd57cb8bc81c81df2c7c207a6

Author: Balandat

CHANGELOG.md

@@ -3,6 +3,12 @@
 The release log for BoTorch.
 
 
+## [0.9.4] - Nov 6, 2023
+
+#### Compatibility
+* Re-establish compatibility with PyTorch 1.13.1 (#2083).
+
+
 ## [0.9.3] - Nov 2, 2023
 
 ### Highlights