Weldable cleanup (#19809)

Content.Shared/Tools/Systems/WeldableChangedEvent.cs

@@ -0,0 +1,12 @@
+using Content.Shared.Tools.Components;
+
+namespace Content.Shared.Tools.Systems;
+
+/// <summary>
+///     Raised when <see cref="WeldableComponent"/> has changed.
+/// </summary>
+[ByRefEvent]
+public readonly record struct WeldableChangedEvent(bool IsWelded)
+{
+    public readonly bool IsWelded = IsWelded;
+}