Replace std::lock_guard and std::lock with std::scoped_lock (#1758)

std::scoped_lock was introduced in C++17 and is strictly better than
std::lock_guard as it supports locking any number of mutexes safely.
It's also easier to use than std::lock for locking multiple mutexes at
once.

hal/src/main/native/athena/Relay.cpp

@@ -100,7 +100,7 @@ void HAL_SetRelay(HAL_RelayHandle relayPortHandle, HAL_Bool on,
     *status = HAL_HANDLE_ERROR;
     return;
   }
-  std::lock_guard lock(digitalRelayMutex);
+  std::scoped_lock lock(digitalRelayMutex);
   uint8_t relays = 0;
   if (port->fwd) {
     relays = relaySystem->readValue_Forward(status);