Disable fsyncing by Git with transactions
When transactions are enabled, the Git commands execute against the transaction's snapshot. These writes don't need to be persisted in the snapshot as the TransactionManager will write them into the write-ahead log and fsync the WAL entry. It is thus wasteful for Git to fsync its writes that are ultimately discarded anyway.
Disable fsyncing by Git and rely on the TransactionManager to fsync its writes.
Closes #5597 (closed)