Reduced Warning Count By 130 For Full Rebuilds (#26518)

* remove deprecated entity coordinate extension functions. Reduces warning count by approximately 50

* final toCoords Removed

* Remove all unused variables and dead code paths

* remove always true variable, should be a cvar or something instead

* remove superfluous variables from tests

Content.Server/Explosion/EntitySystems/ExplosionSystem.Processing.cs

@@ -1,4 +1,3 @@
-using System.Linq;
 using System.Numerics;
 using Content.Shared.CCVar;
 using Content.Shared.Damage;
@@ -17,7 +16,6 @@ using Robust.Shared.Random;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 using TimedDespawnComponent = Robust.Shared.Spawners.TimedDespawnComponent;
-using Content.Server.Atmos.Components;
 using Content.Server.Atmos.EntitySystems;
 
 namespace Content.Server.Explosion.EntitySystems;
@@ -48,13 +46,6 @@ public sealed partial class ExplosionSystem
     /// </summary>
     private Explosion? _activeExplosion;
 
-    /// <summary>
-    ///     While processing an explosion, the "progress" is sent to clients, so that the explosion fireball effect
-    ///     syncs up with the damage. When the tile iteration increments, an update needs to be sent to clients.
-    ///     This integer keeps track of the last value sent to clients.
-    /// </summary>
-    private int _previousTileIteration;
-
     /// <summary>
     /// This list is used when raising <see cref="BeforeExplodeEvent"/> to avoid allocating a new list per event.
     /// </summary>
@@ -112,8 +103,6 @@ public sealed partial class ExplosionSystem
                 if (_activeExplosion == null)
                     continue;
 
-                _previousTileIteration = 0;
-
                 // just a lil nap
                 if (SleepNodeSys)
                 {