[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.Server/StationEvents/Events/SpaceNinjaSpawn.cs

@@ -1,81 +0,0 @@
-using Content.Server.GameTicking;
-using Content.Server.GameTicking.Rules;
-using Content.Server.GameTicking.Rules.Configurations;
-using Content.Server.Ninja.Systems;
-using Content.Server.StationEvents.Components;
-using Content.Server.Station.Components;
-using Robust.Server.GameObjects;
-using Robust.Shared.Map;
-using Robust.Shared.Map.Components;
-using Robust.Shared.Prototypes;
-using Robust.Shared.Random;
-using System.Linq;
-
-namespace Content.Server.StationEvents.Events;
-
-/// <summary>
-/// Event for spawning a Space Ninja mid-game.
-/// </summary>
-public sealed class SpaceNinjaSpawn : StationEventSystem
-{
-    [Dependency] private readonly NinjaSystem _ninja = default!;
-    [Dependency] private readonly IPrototypeManager _proto = default!;
-    [Dependency] private readonly IRobustRandom _random = default!;
-    [Dependency] private readonly GameTicker _ticker = default!;
-    [Dependency] private readonly SharedTransformSystem _transform = default!;
-
-    public override string Prototype => "SpaceNinjaSpawn";
-
-    public override void Started()
-    {
-        base.Started();
-
-        if (StationSystem.Stations.Count == 0)
-        {
-            Sawmill.Error("No stations exist, cannot spawn space ninja!");
-            return;
-        }
-
-        var station = _random.Pick(StationSystem.Stations);
-        if (!TryComp<StationDataComponent>(station, out var stationData))
-        {
-            Sawmill.Error("Chosen station isn't a station, cannot spawn space ninja!");
-            return;
-        }
-
-        // find a station grid
-        var gridUid = StationSystem.GetLargestGrid(stationData);
-        if (gridUid == null || !TryComp<MapGridComponent>(gridUid, out var grid))
-        {
-            Sawmill.Error("Chosen station has no grids, cannot spawn space ninja!");
-            return;
-        }
-
-        // figure out its AABB size and use that as a guide to how far ninja should be
-        var config = (NinjaRuleConfiguration) Configuration;
-        var size = grid.LocalAABB.Size.Length / 2;
-        var distance = size + config.SpawnDistance;
-        var angle = _random.NextAngle();
-        // position relative to station center
-        var location = angle.ToVec() * distance;
-
-        // create the spawner, the ninja will appear when a ghost has picked the role
-        var xform = Transform(gridUid.Value);
-        var position = _transform.GetWorldPosition(xform) + location;
-        var coords = new MapCoordinates(position, xform.MapID);
-        Sawmill.Info($"Creating ninja spawnpoint at {coords}");
-        var spawner = Spawn("SpawnPointGhostSpaceNinja", coords);
-
-        // tell the player where the station is when they pick the role
-        _ninja.SetNinjaStationGrid(spawner, gridUid.Value);
-
-        // start traitor rule incase it isn't, for the sweet greentext
-        var rule = _proto.Index<GameRulePrototype>("Traitor");
-        _ticker.StartGameRule(rule);
-    }
-
-    public override void Added()
-    {
-        Sawmill.Info("Added space ninja spawn rule");
-    }
-}