Mark sync_state_genSyncSpec JSON-RPC as safe (#10832)

* Mark sync_state_genSyncSpec JSON-RPC as safe

* Note that parameter is unused

* Ideally I'd wait for compilation to be finished before pushing, but it's really taking a long time

* Remove deny_unsafe parameter

* Remove unused dependency

substrate/bin/node/rpc/src/lib.rs

@@ -165,7 +165,6 @@ where
 			client,
 			shared_authority_set,
 			shared_epoch_changes,
-			deny_unsafe,
 		)?,
 	));