[Revert] Reverts Ninja (#15516)

* Revert "[Antag] add space ninja as midround antag (#14069)"

This reverts commit c1cda0dbf8.

* Revert "[Fix] move ninja objectives into NinjaRole (#15490)"

This reverts commit 251f429fb3.

Content.Shared/Ninja/Components/SpiderChargeComponent.cs

@@ -1,17 +0,0 @@
-namespace Content.Shared.Ninja.Components;
-
-/// <summary>
-/// Component for the Space Ninja's unique Spider Charge.
-/// Only this component detonating can trigger the ninja's objective.
-/// </summary>
-[RegisterComponent]
-public sealed class SpiderChargeComponent : Component
-{
-    /// Range for planting within the target area
-    [DataField("range")]
-    public float Range = 10f;
-
-    /// The ninja that planted this charge
-    [ViewVariables]
-    public EntityUid? Planter = null;
-}