fix: update horde_model_reference version constraint

This is to guard against an upcoming (breaking) release of horde_model_reference.

Author: tazlin

requirements.txt

@@ -6,7 +6,7 @@ certifi # Required for SSL cert resolution
 horde_sdk~=0.17.1
 horde_safety~=0.2.3
 horde_engine~=2.20.12
-horde_model_reference>=0.9.2
+horde_model_reference~=0.9.2
 
 python-dotenv
 ruamel.yaml