Remove Python2 style object inheritance (#3597)

Summary: Python3 makes the use of `(object)` in class inheritance unnecessary. Let's modernize our code by eliminating this.

Reviewed By: aaronenyeshi

Differential Revision: D48957872

examples/hubert/utils/kmeans.py

@@ -135,7 +135,7 @@ def learn_kmeans(
     _LG.info("Finished training the KMeans clustering model successfully")
 
 
-class ApplyKmeans(object):
+class ApplyKmeans:
     def __init__(self, km_path, device):
         import joblib