Delete hg_sync monad subcommands

Summary:
# This stack
We are removing hg_sync which is not used anymore
https://docs.google.com/document/d/17pccU80ngYcggsbGamiuDjXy8WN63kB_UQff0kayz2E/edit?tab=t.0

# This diff
Delete hg_sync monad subcommands, the hg_sync subcommand itself was deleted in D74245659 but the subcommands within it were not

Reviewed By: lmvasquezg

Differential Revision: D74332628

fbshipit-source-id: 33f08a36b85a33f38b096c32f6e4b0f599ea1126

Author: Clara Rull