Fix tethergun (#16612)

Content.Shared/Weapons/Misc/BaseForceGunComponent.cs

@@ -11,7 +11,7 @@ public abstract class BaseForceGunComponent : Component
     /// The entity the tethered target has a joint to.
     /// </summary>
     [DataField("tetherEntity"), AutoNetworkedField]
-    public EntityUid? TetherEntity;
+    public virtual EntityUid? TetherEntity { get; set; }
 
     /// <summary>
     /// The entity currently tethered.

Content.Shared/Weapons/Misc/TetherGunComponent.cs

@@ -8,6 +8,12 @@ public sealed partial class TetherGunComponent : BaseForceGunComponent
     [ViewVariables(VVAccess.ReadWrite), DataField("maxDistance"), AutoNetworkedField]
     public float MaxDistance = 10f;
 
+    /// <summary>
+    /// The entity the tethered target has a joint to.
+    /// </summary>
+    [DataField("tetherEntity"), AutoNetworkedField]
+    public override EntityUid? TetherEntity { get; set; }
+
     /// <summary>
     /// The entity currently tethered.
     /// </summary>

Resources/Prototypes/Entities/Objects/Weapons/Guns/Launchers/launchers.yml

@@ -160,6 +160,8 @@
   description: Manipulates gravity around objects to fling them at high velocities.
   components:
     - type: TetherGun
+      frequency: 5
+      dampingRatio: 4
     - type: PowerCellDraw
     - type: Sprite
       sprite: Objects/Weapons/Guns/Launchers/tether_gun.rsi