Fix typo

Co-authored-by: Alfonso Acosta <[email protected]>

cmd/soroban-rpc/lib/preflight/src/lib.rs

@@ -16,7 +16,7 @@ extern crate soroban_env_host_prev;
 extern crate soroban_simulation_curr;
 extern crate soroban_simulation_prev;
 
-// We support two different versions of soroban simutlaneously, switching on the
+// We support two different versions of soroban simultaneously, switching on the
 // protocol version each supports. This is the exact same mechanism we use in
 // stellar-core to switch soroban hosts on protocol boundaries, and allows
 // synchronously cutting over between significantly different versions of the