fix unit test

Author: ahsan-z-khan

src/sagemaker/workflow/steps.py

@@ -119,10 +119,10 @@ class CacheConfig:
     @property
     def config(self):
         """Configures caching in pipeline steps."""
-        config = {'Enabled': self.enable_caching}
+        config = {"Enabled": self.enable_caching}
         if self.expire_after is not None:
-            config['ExpireAfter'] = self.expire_after
-        return {'CacheConfig': config}
+            config["ExpireAfter"] = self.expire_after
+        return {"CacheConfig": config}
 
 
 class TrainingStep(Step):