stop using thrift/py compiler
stop using thrift/py compiler

Summary: stop using `thrift/py` compiler since its usage is now migrated to `t_mstch_cpp2_generator`.

Reviewed By: yfeldblum

Differential Revision: D15052433

fbshipit-source-id: 0f1bc32b79e3aea14d520d3f7a1420da0cd01f1d

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift