Code cleanup: radio jammer (#29052)

* Code cleanup for radio jammer

* More Entity<T> for the people, and fix an accidental variable reuse

Content.Server/Radio/Components/ActiveRadioJammerComponent.cs

@@ -1,12 +0,0 @@
-using Content.Server.Radio.EntitySystems;
-
-namespace Content.Server.Radio.Components;
-
-/// <summary>
-/// Prevents all radio in range from sending messages
-/// </summary>
-[RegisterComponent]
-[Access(typeof(JammerSystem))]
-public sealed partial class ActiveRadioJammerComponent : Component
-{
-}