Prevent subfloor melee attacks (#12899)

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Shared/Interaction/Events/GettingAttackedAttemptEvent.cs

@@ -0,0 +1,7 @@
+namespace Content.Shared.Interaction.Events;
+
+/// <summary>
+/// Raised directed on the target entity when being attacked.
+/// </summary>
+[ByRefEvent]
+public record struct GettingAttackedAttemptEvent(bool Cancelled);