message: fix a data race on Debug builds
  On Debug builds, HeapAllocatorArena needs LockingPolicy::Mutex because
  it uses a TrackingPolicy, which needs to be synchronized.
  On Release builds, HeapAllocatorArena doesn't need a LockingPolicy
  because HeapAllocator is intrinsically synchronized as it relies on
  heap allocations (i.e.: malloc/free)
diff: @@ -35,9 +35,11 @@ static constexpr size_t CONFIG_COMMAND_BUFFERS_SIZE = 3 * CONFIG_MIN_COMMAND
  #ifndef NDEBUG
  +// on Debug builds, HeapAllocatorArena needs LockingPolicy::Mutex because it uses a
  +// TrackingPolicy, which needs to be synchronized.
  using HeapAllocatorArena = utils::Arena<
  utils::HeapAllocator,
  - utils::LockingPolicy::NoLock,
  + utils::LockingPolicy::Mutex,
  utils::TrackingPolicy::DebugAndHighWatermark>;
  using LinearAllocatorArena = utils::Arena<
  @@ -47,6 +49,8 @@ using LinearAllocatorArena = utils::Arena<
  #else
  +// on Release builds, HeapAllocatorArena doesn't need a LockingPolicy because HeapAllocator is
  +// intrinsically synchronized as it relies on heap allocations (i.e.: malloc/free)
  using HeapAllocatorArena = utils::Arena<
  utils::HeapAllocator,
  utils::LockingPolicy::NoLock>;
  