Mark Objects.py as a generated file. (project-chip#10889)

This way it won't clutter up reviews by default.

Author: bzbarsky-apple

.gitattributes

@@ -5,4 +5,5 @@
 # And some specific generated files
 src/controller/python/chip/clusters/CHIPClusters.cpp linguist-generated
 src/controller/python/chip/clusters/CHIPClusters.py linguist-generated
+src/controller/python/chip/clusters/Objects.py linguist-generated
 src/darwin/Framework/CHIPTests/CHIPClustersTests.m linguist-generated